Foundry Forging Pune University MCQs
Foundry Forging Pune University MCQs
This set of Foundry Multiple Choice Questions & Answers focuses on “Patterns and its Functions”.
1. _________________ is termed as a replica of the object to be made by the casting process.
a) Pattern
b) Core
c) Riser
d) Spruee
Answer: a
Explanation: A Patten is a casting double which has allowances, provision of the core prints which is used to make a casting. It is a replica into which molten metal will be poured during the casting processes and later the metal is hardened and a component is obtained.
2. The final dimensions of the pattern are ______ the final dimensions of the casting required.
a) Similar to
b) Different from
c) Equal to
d) Approximate to
Answer: b
Explanation: The Pattern is made given the allowances as required. Once the casting is prepared, the casting is machined to get the required dimensions. Usually, the dimensions of the pattern are more than the dimensions of the castings.
3. The contractions in the materials depend upon the metallurgical transformation taking place during which of the following process?
a) Solidification
b) Melting
c) Calcination
d) Smelting
Answer: a
Explanation: When a metal undergoes solidification, it undergoes a decrease in volume which is called contraction and hence is it is a major parameter in the metallurgical transformation which is taken into consideration while designing any component for foundry applications.
4. The shrinkage value given to the pattern must be _________ for the outer dimensions which are to be restrained.
a) Lower
b) Higher
c) Equal
d) Does not alter anything
Answer: b
Explanation: In a dry sand core, the centre of the casting may restrain the casting from the contraction but the edges are not restrained. Thus, it is desirable to provide a higher shrinkage allowance.
5. ______________ is used to reduce the chances of damaging the mould cavity.
a) Draft Allowance
b) Shrinkage Allowance
c) Finish Allowance
d) Machining Allowance
Answer: a
Explanation: At the time of withdrawing a pattern from the sand mould, the vertical faces of the pattern are in continual contract with sand which damages the mould cavity. Hence the pattern is tapered from the parting line and it is called as the draft allowance.
6. ______________ pattern is expected to be entirely in the drag.
a) Single piece pattern
b) Split piece pattern
c) Gated piece pattern
d) Match plate pattern
Answer: a
Explanation: Single piece pattern is used for various applications. As one of the surfaces is expected to be flat the single piece pattern is expected to be in drag Sometimes the flat surface of the Single piece pattern could also be made to function as a parting line.
7. The split piece pattern is aligned perfectly using ________
a) Screw Pins
b) Dowel Pins
c) T-Pins
d) Straight pins
Answer: b
Explanation: The dowel pins match with the precisely made holes in the drag half of the pattern and thus align the two halves . The dowel pins are used as location guides for the adjustments of the cope and the drag.
8. _________ is used for the pattern in the full mould process.
a) Polythene
b) Polysilicate foam
c) Polyurethane foam
d) Polystyrene foam
Answer: d
Explanation: In the full moulding process, the foam evaporates soon after the metal is poured. Hence Polystyrene foam is used as it is light and can easily be formed into any shape required. It can be used as light duty work for small castings.
9. Hand cutting of runners and gates is eliminated in ______________
a) Split Pattern
b) Single piece pattern
c) Gated Pattern
d) Match Plate Pattern
Answer: c
Explanation: Gated Pattern is an improvement over simple pattern where gating and runner system is integral with a pattern. A Gated Pattern consists if the moulding and control patterns, jigs, the drying plates and the stripping place all embedded in it.
10. __________ is a mould forming tool is the hand of Foundry men.
a) Pattern
b) Arch
c) Sand
d) Gating System
Answer: a
Explanation: Mould forming is a one by which the design of the casting which is to be produced is formed. The Pattern is one of the most important parts of the process by which the mould is formed. Hence the foundry men popularly call it as a mould forming tool.
This set of Foundry Interview Questions and Answers focuses on “Materials used for Patterns”.
1. _______________ used in patterns as heat resistant materials.
a) Fluxes
b) Refractories
c) Resin
d) Acids
Answer: b
Explanation: The refractories are called the heat resistant materials as they can withstand high temperatures without being fused. This is an important property used in design of patterns.
2. Which of the following types of Cast Iron is not included in the formation of castings?
a) Gray Cast Iron
b) Malleable Cast Iron
c) Hematite
d) White Cast Iron
Answer: c
Explanation: Hematite is an iron ore. It can only be used after extracting the iron from it. Direct application is not permitted.
3. Which of the following fluxes are not used for the melting of Magnesium alloys?
a) Magnesium Chloride
b) Magnesium Chloride
c) Barium Chloride
d) Chlorine
Answer: d
Explanation: The Chlorine here is a gaseous flux. It is used to remove the dissolved hydrogen and entrapped dross. The entrapped dross is not present in the magnesium alloys.
4. Which of the following is a drawback of the aluminum used in pattern making?
a) Thermal Conductivity
b) Mass Density
c) Tensile Strength
d) Melting Point
Answer: c
Explanation: The tensile strength of aluminum is very low. This makes it non-suitable for the pattern making applications.
5. The strong anisotropy exhibited in _________ under deformed condition is a disadvantage when it comes to foundry applications.
a) Zinc
b) Iron
c) Aluminium
d) Steel
Answer: a
Explanation: Zinc shows lack of dimensional stability under the aging condition and is susceptible to intergranular corrosion. Hence it cannot be used widely in foundry applications.
6. ______________ is the most commonly used deoxidizer used in foundry.
a) Tungsten
b) Molybdenum
c) Silicon
d) Titanium
Answer: c
Explanation: Silicon is used in the form of Silicon dioxide as it has the ability to resist oxidation in steel. Hence it is termed as the best deoxidizer.
7. Which of the following has the highest carbide forming tendency of all alloying elements?
a) Titanium
b) Chromium
c) Vanadium
d) Cobalt
Answer: a
Explanation: Titanium has no effect on the hardening ability and it inhibits grain growth. Hence the titanium has highest carbide forming tendency.
8. _________ patterns are free from knots and other common defects.
a) Wood
b) Metal
c) Plastic
d) Wax
Answer: a
Explanation: The straight grained and properly seasoned wood such as Mahogany, Teak, Deodar etc., are free from knots and are easy to work with. There are very few defects in casting when worked with these patterns.
9. ____________ is considered as the best pattern and is widely used in foundry.
a) Aluminium
b) Steel
c) Zinc
d) Nickel
Answer: a
Explanation: Aluminium has long durability, excellent resistance to corrosion. Hence, aluminium is usually referred to as the best pattern material.
10. The pattern that has application in the investment casting process is __________
a) Plaster
b) Wax
c) Wood
d) Cast Iron
Answer: b
Explanation: Wax Patterns provide good surface finish and impart high accuracy. Hence, they have great use in the Investment Casting Process.
This set of Foundry Multiple Choice Questions & Answers focuses on “BIS Colour Coding”.
1. Which of the following is not a function of a Colour Pattern?
a) To show the location of the parting surface
b) To identify the parts of the castings
c) Indicate the type of metal to be cast
d) Identify the core prints
Answer: a
Explanation: The Colour Pattern given by the American System of Colour Code for Castings is to show the location of the pattern construction. The location of the parting surface is depicted by the separating part of the cope and drag or the flat surface in case of single piece pattern.
2. Diagonal Black Stripes with clear varnish on is used to strengthen the weak pattern.
a) True
b) False
Answer: a
Explanation: According to the American System of Colour Code for Casting the Diagonal Black Stripes with clear varnish on, is used to strengthen the weak pattern and it is also used to shorten the castings. This code is fixed for the above functions.
3. The orange colour cannot be used on the surface of the cast which is not finished and left.
a) True
b) False
Answer: b
Explanation: For the surfaces of the unfinished castings which are left to be either dispatched or kept in inventory are marked by orange colour as well. According to the BIS Colour Code, the colour Orange and Red are used for this function.
4. __________ colour indicated the seats of the loose pattern.
a) Yellow strip on Red
b) Black strip on Green
c) Purple strip on Pink
d) Red strip on Yellow
Answer: a
Explanation: The Loose piece pattern is the one in which there is one piece of solid part and has the projections which are formed with the help of loose pieces. These loose pieces are shown in yellow strips on red colour according to the BIS Colour code.
5. The function of the colour code is to impart aesthetic look to the castings.
a) True
b) False
Answer: b
Explanation: The BIS Colour Code System has a function to help the mould maker, distinguish between the parts of the castings and understand what operation is to be performed. It is usually not concerned with the aesthetic looks. They are given only if the customer demands aesthetic looks.
6. The American Colour Code scheme has its applications in ________
a) Foundry
b) Mines
c) Assembly Lines
d) Product Design
Answer: a
Explanation: The foundry men and workers faced a lot of problems to identify castings. Hence the American Society formulated this code for the better understanding of the sorting of castings.
7. The Pattern Colour code can be interchanged for different parts according to the design.
a) True
b) False
Answer: b
Explanation: The Colour code for castings is given to establish uniformity and if they are interchanged, wrong information is obtained and can result in loss and rework. Hence, the change in the colour according to the pattern is not desirable.
8. No colour on the casting surface indicates that it is a parting surface.
a) True
b) False
Answer: a
Explanation: The American Colour code for castings has prescribed that the parting surfaces are to be given no colour as they are separable and may/may not be used later.
9. Purple colour is used for ________
a) Machineable parts
b) Non-machineable parts
c) Parting surface
d) Cannot be used on any surface
Answer: d
Explanation: The purple colour is not allotted to any function in the American Colour code pattern. Hence, even if it is applied on any surface it is not possible to determine its function. The application of purple if done is solely due to the industry rules or customer needs.
10. Black Colour is to be applied on the castings which are to be __________
a) Machined
b) Not to be machined
c) Filed
d) Stored
Answer: a
Explanation: According to the American System of Colour Code for casting which are to be machined is Black. This is colour is fixed for the above function and it cannot be changed. It is followed by many industries.
This set of Foundry Questions and Answers for Campus interviews focuses on “Binders and its Applications”.
1. _________________ is a binder that becomes firm at room temperature.
a) Dextrin
b) Pitch
c) Rubber Latex
d) Molasses
Answer: c
Explanation: Rubber Latex is rubber cement. Silica is mixed with water and this latex which is obtained of the plant is added to it. This mixture is then rammed and it hardens at the room temperature and has excellent binding properties.
2. __________ is a binder that becomes hard on baking.
a) Marine animal oil
b) Wood Resin
c) Oil Resin
d) Coal tar resin
Answer: a
Explanation: Marine animal oil is of the group of binders that do not develop their strength by any kind of physical or chemical changes, rather they are baked to harden them. Usually, Whale oil is used for binding applications.
3. Which of the following is not a protein binder?
a) Gelatin
b) Casein
c) Glues
d) Molasses
Answer: d
Explanation: Molasses is a by-product of the sugar industry. After testing for its applications, molasses was not found to be protein rich; whereas the Gelatin got from meat, casein made from milk and the glue got from plants is all protein rich.
4. __________ is a binder made from starch.
a) Cereal Binder
b) Pitch
c) Limed wood resin
d) Dextrin
Answer: d
Explanation: Dextrin is a carbohydrate which is produced by hydrolysis of starch or glucose. They are low molecular weight components and have significant binding properties. It is low cost and highly efficient binder.
5. _________________ are not pure binders but they serve to improve the collapsibility of the core.
a) Clay Binders
b) Saw dust and Wood flour
c) Marine Animal Oil
d) Sulfate Binder
Answer: b
Explanation: Saw dust and Wood flour have very little adhesive strength and it cannot perform well in complex application. It is rarely used for the chances of core collapsing are high. It is used in grain filler compounds only.
6. ______________ is the mechanical binder used in Masonry.
a) Bond stones
b) Gypsum
c) Cement
d) Silicon Fluoride
Answer: a
Explanation: Bond Stone is a stone which is strong and long enough to extend to the wall to its full thickness in order to join it. Hence it is used in Masonry.
7. _______________ is a binder that is used in the no-bake sand cores.
a) Gum Resin
b) Synthetic Resin
c) Coal tar Resin
d) Wood Resin
Answer: b
Explanation: The synthetic resins like phenol and urea formaldehyde are used as binders. They are mixed with hardeners to bring the chemical reaction. In this process, strength development takes place in a few minutes.
8. Which of the following is not a function of a core binder?
a) Hold the sand grains together
b) Give strength to the core
c) Not to impart collapsibility to core
d) Make cores to resist erosion and breaking
Answer: c
Explanation: Core is a disposable item used in Foundry. The core binder has a function of imparting adequate collapsibility to the cores before their purpose is served.
9. ____________ is fine pulverized material used as a binder.
a) Water
b) Sodium Silicate
c) Iron Oxide
d) Silica Flour
Answer: d
Explanation: The Silica Flour is fine pulverized materials that are used greatly to increase the amount of oil necessary in oil sand mixtures. This binder is used only when the sand properties are fixed and it need not vary.
10. ___________ are polymerized to strong solids to be used as binders.
a) Bentonite
b) Fire Clay
c) Epoxy Resins
d) Phenol Formaldehyde
Answer: d
Explanation: Phenol Formaldehyde is synthetic resins which are thermosetting. They are dry powder or liquid. They are heated to get excellent binding properties.
This set of Foundry Questions and Answers for Freshers focuses on “Types of Binders in the Moulding Sand, Types of Base Sand”.
1. _________________ binders are used for large dry sand cores.
a) Sulfate Binders
b) Pitch
c) Dextrin
d) Gelatinalized Starch
Answer: a
Explanation: Sulfate Binders are compounds of wood sugars produced in paper pulp process. It is being used in the large and dry sand cores as an ingredient of the Pitch as it contains the specified qualities required.
2. __________ is a binder that resists molten metal.
a) Coal tar
b) Core oil
c) Pitch
d) Chamotte
Answer: c
Explanation: Pitch is a coal tar product. In the form of ground powder, the pitch may be added to up to 3% or more. With the presence of the molten metal around the core, pitch develops the hot strength to resist the molten metal.
3. ______________ contributes towards the baked strength of molding sand.
a) Natural Resin
b) Carbon
c) Olivine
d) Core Oil
Answer: d
Explanation: The vegetable oils, mineral oils are regarded as the core oils. Their content in the sand varies from 0.5% to 3.0% by weight and hence they contribute to in increasing baked strength of molding sand.
4. __________ is an excellent water soluble binder.
a) Cereal Binder
b) Zircon
c) Dextrin
d) Silica Sand
Answer: c
Explanation: Dextrin is a water soluble binder. The air hardens rapidly and resists core sagging during the handling. The increased moisture content develops the higher tensile strength, baked scratch and the edge hardness.
5. _________________ is used as the core coating medium.
a) Fire Clay
b) Plumbago
c) Bentonite
d) Cement
Answer: b
Explanation: Just like mould coating, Core coating is also done. It is known as Core washing, dressing etc. Core Surfacing is done my Plumbago or Silica Flour. Plumbago is obtained from plants and imparts a good finishing. It is applied by dipping, spraying etc.
6. _________________ sands are best molding sands.
a) Refractory Sand
b) Loam Sand
c) Natural Sand
d) Synthetic Sand
Answer: a
Explanation: Refractory Sands maintain their shape and other characteristics even at very high temperatures while they are in contact with the molten metals. Hence they are termed as the best molding sands.
7. __________ is refractory sand that can be molded to intricate shape.
a) Quartz
b) Olivine
c) Bentonite
d) Clays
Answer: b
Explanation: Olivine is refractory sand. When packed as the mold cavity, they remain sufficiently porous or permeable to give vents to the mould gases to escape out. Hence they are chemically immune and can be molded in intricate shapes.
8. Which of the following cannot be used repeatedly for making moulds?
a) Sillimanite
b) Dolomite
c) Natural Sand
d) Silica Sand
Answer: c
Explanation: The Natural Sands are to be used for making moulds as soon as it is received from the source. The content of the binding particles is less which makes it unsuitable for the making of moulds which are needed repeatedly.
This set of Foundry Multiple Choice Questions & Answers focuses on “Requirements of the Base Sand”.
1. The Natural Sand needs only water to mix before making moulds.
a) True
b) False
Answer: a
Explanation: The Natural sand is obtained from sources like deserts, lakes, riverside beds etc. It has a certain quantity of natural binders such as clay. The water is mixed before making of the mould is necessary to make it easy for molding.
2. Which of the following is not included in the Natural Sand?
a) Organic Matter
b) Water
c) Clay
d) Graphite
Answer: d
Explanation: Natural Sand is usually imported from the banks of the water sources. Hence the water content, clay and organic matter are expected from the sand content. However, the chances of the Graphite content are minimal.
3. Synthetic Sand possess greater refractoriness.
a) True
b) False
Answer: a
Explanation: The Synthetic sands contain uniform grain size. They acquire proper mold ability with less moisture. They have high permeability and hence greater refractoriness (above 3000 o C).
4. ____________ sand has higher clay content than ordinary sand.
a) Silica Sand
b) Loam Sand
c) Illite
d) Limonite
Answer: b
Explanation: Loam Sand us composed of Sand particles and very fine clay particles. It is found in the successful farming regions known for fertile land. As it is softer than ordinary sand, it has higher clay content.
5. Natural Sand contains 50% clay.
a) True
b) False
Answer: b
Explanation: Natural Sand has binding materials in very less quantity. The Binding materials are to be externally added and the quantity required is less. Loam sand has 50% clay and is very softer than Natural Sand.
6. ______________ requires less proportion of binders.
a) Natural Sand
b) Synthetic Sand
c) Loam Sand
d) Silica Sand
Answer: b
Explanation: Synthetic Sands are made by adding binders. Synthetic Sand properties are enhanced by adding external chemical agents which technically lessens the proportion of binders.
7. Natural Sand is mixed with bentonite gets its properties improved and is called Synthetic Sand.
a) True
b) False
Answer: b
Explanation: When Natural sand is mixed with a binder such as Bentonite, the properties of the Natural Sand such as green strength, compressive strength is increased but it also retains its original properties. It becomes semi-synthetic sand.
8. Synthetic Sand is formulated sand.
a) True
b) False
Answer: a
Explanation: Synthetic sand consists of Natural Sand, Binder and Moisture. It is done in order to acquire certain desirable properties not possessed by natural sands. They are prepared using all these components. Hence it is called as the formulated sand.
This set of Foundry Questions and Answers for Aptitude test focuses on “Type of Sand Moulds”.
1. _________________ is a container which when poured with molten metal produce a casting of the shape of the mould.
a) Mould
b) Pattern
c) Core
d) Spruee
Answer: a
Explanation: Prepared molding sand is packed rigidly around a pattern and when the pattern is withdrawn, a cavity corresponding to the shape of the pattern remains in the sand and is called as the mould.
2. In Green Sand Mould, the molten metal is poured while it is in a wet state.
a) True
b) False
Answer: a
Explanation: The non-dried condition of the sand is called as the green sand condition. It is used in damp condition and contains free water. Hence the molten metal is poured while it is in the wet state to ensure better quality castings.
3. Dry Sand Moulds are used for small and medium sized castings.
a) True
b) False
Answer: b
Explanation: Dry Sand is nothing baked Green Sand. The moulds are filled with the green sand and then the entire mold is dried in ovens before molten metal is poured They have high strength and permeability. Hence, the dry sand moulds are used for large castings as they are not suitable for small castings.
4. _____________ Binders are used to harden the skin dried moulds.
a) Linseed Oil
b) Marine Oil
c) Vegetable Oil
d) Synthetic Resins
Answer: a
Explanation: Linseed oil is added with molding sand in the green condition and then the skin of the mould cavity is dried up with the help if gas or flame torches. The structure after drying appears to be like dried skin. Hence the name is Skin dried moulds.
5. ______________ is made by assembling a number of cores made individually in separate core boxes and baked.
a) Dry Sand Mould
b) Air dried Mould
c) Skin dried Mould
d) Core Sand Mould
Answer: d
Explanation: The cores are made with recesses and projections so that they can be fitted together to make a mould. Hence, a core sand mould is said to be an assembly of such components.
6. Metal Mould provide high dimensional accuracy.
a) True
b) False
Answer: a
Explanation: Metal Moulds are permanent moulds. It is manufactured by casting and consequent machining of the mould cavity. Hence the dimensional accuracy got is high. The Metal moulds retain their shape for longer time and provide dimensional accuracy.
7. _____________ is used to make a metallic die in Investment mould.
a) Sweep Pattern
b) Master Pattern
c) Single Piece Pattern
d) Skeleton Pattern
Answer: b
Explanation: The surface finish and the accuracy in dimensions of the castings are high in Investment mould. Hence, the master pattern is used in the Investment mould. The pattern is reusable as well.
8. _________ is produced with the help of heated iron/steel patterns.
a) Loam Mould
b) Shell Mould
c) Ceramic Mould
d) Metal Mould
Answer: b
Explanation: Shell mould is a mixture of fine sand and phenolic resin used to produce shells. Shells are assembled to form mould which is poured with molten metal. They give a good surface finish and dimensional accuracy. Hence they are produced with steel and iron.
9. A Ceramic Mould is used to produce thin sections of the high melting point metals and alloys.
a) True
b) False
Answer: a
Explanation: A ceramic mould can produce castings which do not need machining. They have an excellent ability to cast high melting point alloys to accurate dimensions irrespective of the thickness of the materials due to their ability to withstand high temperature.
10. IC Engine pistons are cast in ___________
a) Investment Moulds
b) Shell Moulds
c) Metal Moulds
d) Ceramic Moulds
Answer: c
Explanation: IC Engine pistons are made up of Aluminum alloy. The IC Engine piston requires a good surface finish and fine grain structure and hence they are made using metal moulds.
This set of Foundry Multiple Choice Questions & Answers focuses on “Methods of Sand Moulding”.
1. In Bench Molding, the height of the bench can be adjusted.
a) True
b) False
Answer: a
Explanation: In Bench Molding, the light and the heavy moulds can be made. Small and the light molds are prepared on benched. The heavy moulds are molded on the floor but they are cope and the drag are rammed on the benches. Hence, it is said that the height of the bench can be adjusted.
2. Which of the following molding method is not used in foundries?
a) Bench
b) Floor
c) Machine
d) Injection
Answer: d
Explanation: The Injection molding process is used for plastic molding. It has no role in the foundry processes and the working materials in foundries are heavier than the plastic.
3. Both Green and Dry Sand Moulds can be made by floor molding.
a) True
b) False
Answer: a
Explanation: Both the medium and large moulds can be made by floor molding. Usually, green sand is used for medium sized castings and dry sand for large castings. Therefore, both the type of moulds can be made by floor molding.
4. In Bench molding, the molder makes the mold while standing.
a) True
b) False
Answer: b
Explanation: The cope and drag are both rammed on bench. The height of the mould can be adjusted. Hence the mould maker has to stand and work on the mould in Bench molding.
5. Non Ferrous castings are especially made on _______________
a) Floor Molding
b) Pit Molding
c) Bench Molding
d) Machine Molding
Answer: c
Explanation: Non-ferrous castings are made by both the type of sand such as Green sand and Dry Sand. These sands are used in the Bench Molding processes. Hence, bench molding is employed in non-ferrous castings.
6. Castings that cannot be made floor molding can be made using ___________
a) Pit Molding
b) Injection Molding
c) Machine Molding
d) Bench Molding
Answer: a
Explanation: Very big castings which cannot be made in flasks are molded in pits dug on the floor. Very large castings can be handled and cast easily through pit molding. In floor molding, the making of such flasks is difficult and not economical.
7. The sides of the pit drag are lined with ____________
a) Binders
b) Bricks
c) Additives
d) Refractories
Answer: b
Explanation: When the molten metal is poured into the cope and drag assembly, the metals start getting solidified and the gases are emitted out. Due to the compactness of the sand, the gases find it difficult to go out. Hence it is lined with bricks t=for east escape of the gases.
8. Gates, runners, pouring basin etc are made in ____________ in pit molding.
a) Cope
b) Drag
c) Pattern
d) Cores
Answer: a
Explanation: The cope is rammed over pit with the pattern position. The cope is an upper part of the assembly where metal is poured in. Hence all these elements are the constituents of the cope.
9. Uniform and consistent castings can be obtained by __________ method in molding.
a) Injection Molding
b) Pit Molding
c) Machine Molding
d) Bench
Answer: c
Explanation: As the operations like ramming, rolling of the mould over, withdrawing the pattern etc, are done by the machines, the operations are done faster and identical. Due to this, consistent products are obtained.
10. Which of the following machines is not used in machine molding?
a) Jolting Machine
b) Sand Slinger
c) Squeezer Machine
d) Mill Hopper
Answer: d
Explanation: It is used for manufacturing of Cement. It is used in its manufacturing. Other machine used in machine molding are: Sand Slinger and Jolt and Squeezer machine.
This set of Foundry Multiple Choice Questions & Answers focuses on “Cores and Types”.
1. __________ is also termed as an obstruction when positioned in the mould.
a) Gate
b) Riser
c) Core
d) Pattern
Answer: c
Explanation: Core is an obstruction which when positioned in the mould, naturally does not permit the molten metal to fill up the space occupied by core. In this way, a core produces hollow castings.
2. Cores are not made up of ___________
a) Sand
b) Wax
c) Plaster
d) Ceramics
Answer: b
Explanation: A core is essentially a body of material which forms a component of the mould. It possesses sufficient strength to be handled as an independent unit. Wax does not contain such properties. Hence it cannot be used to make cores.
3. Cores are required to create ________________
a) Gates
b) Spruees
c) Undercuts
d) Recesses
Answer: d
Explanation: Cores are employed as inserts in moulds to form design features that are otherwise extremely difficult to produce by the simple molding method. Hence cores are required to create the recesses, undercuts and interior cavities that are often a part of castings.
4. Cores may be used to form the gating system of the large size.
a) True
b) False
Answer: a
Explanation: Cores provide means of forming the main internal cavities. Cores may provide external undercut features. Hence they may be used to form the large size for the gating system.
5. Smaller cores can be made manually in hand rammed core boxes.
a) True
b) False
Answer: a
Explanation: Small cores need to have a smooth surface to ensure a smooth casting. These ingredients which do not generate much mold gases. Small cores can be made for limited production and are manually made in hand filled core boxes.
6. Which of the following is not a step in the core making process?
a) Sand Preparation
b) Machining
c) Setting
d) Finishing
Answer: b
Explanation: Machining is a process which is composed of various operations such as turning, drilling, milling, boring etc. These operations have no significance in the core making process and hence it is not a part of it.
7. The weak cores are not reinforced with steel wires to strengthen them.
a) True
b) False
Answer: b
Explanation: Core box is usually placed on work bench. It is filled with already mixed and prepared core sand. It is rammed by hand and extra sand is removed from the core box. Weak cores are usually reinforced to impart high strength and permeability.
8. Core prints are extra projections provided on the pattern.
a) True
b) False
Answer: a
Explanation: Core prints form core seats in the mould when the pattern is embedded in the sand for making the mould. Core seats are provided to support all types of cores.
9. ________ cores are used to produce pipe bends.
a) Left and Right hand core box
b) Split box core box
c) Half core box
d) Pump core box
Answer: a
Explanation: The left and right hand cores are used to make cores for producing pipe bends. Half of the pipe bend core is made into each core box. The two halves of the pipe bend thus rammed are baked and cemented to make a full core.
10. __________ core boxes cost the least of all the core boxes.
a) Loose piece core box
b) Strickle core box
c) Gang core box
d) Half core box
Answer: b
Explanation: In the Strickle core box, the top portion is done by the strickle board cut. It strikes off the excess sand. A regular, irregular or the unsymmetrical shape is difficult to produce on core box but can be cut on wooden strickle board. Hence it costs less.
This set of Foundry Interview Questions and Answers for freshers focuses on “Methods of Making Cores”.
1. Core sand can be rammed in a dump type core box on a ______________
a) Jolt Machine
b) Sand Slinger
c) Core roll over machine
d) Core extrusion machine
Answer: a
Explanation: In a jolting machine, the core box filled with sand is mounted on a jolt table which is raised to a certain height and then dropped under on its own weight. Sand gets rammed due to this sudden fall.
2. ____________ machine is similar to the mold roll over machine.
a) Core blowing machine
b) Squeezing machine
c) Core roll over machine
d) Core extrusion machine
Answer: c
Explanation: The core roll over machine is similar to the mold roll over machine. Core box is rammed with the sand using the jolt principle. Core box is then rolled over, the core is withdrawn. After this, the core box is sent to the baking oven.
3. Sand Slinger is used for filling and ramming a large core.
a) True
b) False
Answer: a
Explanation: Sand Slinger makes use of a high speed rotating sand impeller which throws the sand in the core box at high velocities. The impact action of the sand stream is responsible for the compacting the core.
4. Cores of which of the following shapes are not produced in core extrusion process:
a) Square
b) Hexagonal
c) Round
d) Random
Answer: d
Explanation: In a core extrusion machine, a die is to be made and fixed at one end. The machine has a hopper through which the core sand is fed to a horizontal spiral conveyor. The cores of basic geometrical shape are only produced in this method.
5. Simple cores of regular shapes and uniform cross-section can be extruded easily on a core extrusion process.
a) True
b) False
Answer: a
Explanation: In a core extrusion machine, the spiral conveyor present is rotated and it forces the core sand through a die of specified shape only. Hence only simple cores of regular shapes and uniform cross section can be extruded from this process.
6. Core boxes to be used on the core blowing machines are made up of ______________
a) Iron
b) Brass
c) Aluminum
d) Carbon
Answer: c
Explanation: The cores produced in the core blowing machines are produced due to the air at high velocity. It is important that the air has to be let out through the vents. The method of forming vents is easily done in aluminum. Hence the core boxes are made up of aluminum.
7. The core boxes are provided with wires perform a function of which of the following component?
a) Riser
b) Gates
c) Vents
d) Shell
Answer: c
Explanation: The incoming air in the core blowing machine with the sand is exhausted through the vents provided in the core-box. The wires in the core boxes automatically provide vent holes in the cores as they are blown off. They are withdrawn before the core is stripped.
8. The sand carrying the compressed air stream in the core blowing machine is responsible for filling the core box and ramming the core.
a) True
b) False
Answer: a
Explanation: Core blowing machine makes use of compressed air ² to blow the sand into the core box at high velocity. Thus, the filling and ramming of the core are done.
9. In the Shell Core making, when the sand blowing is employed, it is preferred to use resin precoated sands to avoid resin segregation.
a) True
b) False
Answer: a
Explanation: In shell core making, the sand is mixed with about 2% to 5% thermosetting resin of phenolic type is either dumped or blown and then when the sand blowing is carried out, resin precoated sand is preferred to impart high permeability and smooth surfaces.
This set of Foundry Questions and Answers for Experienced people focuses on “Binders used in Making Cores”.
1. ____________ is the oldest binder used in making cores.
a) Coal tar
b) Dextrin
c) Molasses
d) Vegetable oil
Answer: d
Explanation: The concept of foundry emerged several years ago. As vegetable oil is considered to have several binding properties, it was used. It gained its popularity due to its wide availability and less expensive in nature.
2. Use of cores is extensively done in the casting of engine blocks.
a) True
b) False
Answer: a
Explanation: The cores are normally a disposable item which gets destroyed to get it out of the component. One of the GM V-8 engines requires five dry sand cores for every casting.
3. The core when mixed with synthetic oil does not require heating.
a) True
b) False
Answer: b
Explanation: The core when mixed with synthetic oil in conjunction with cereal or clay is to be baked in convention oven between 200 and 250 o C so that the heat causes the binder in polymerizing. This helps the binder perform well.
4. The cores produced by the binder process called hot-box process is called _________
a) Shell core
b) Resin bond cores
c) No-bake cores
d) Dry sand cores
Answer: a
Explanation: The hot-box process uses a thermoset and catalyst for a binder. The cores produced by this process are called shell cores because only the outside layer is hardened when it comes into contact with the hot core box.
5. In Cold-box process, the binder that is used to harden the core is by liquid binders.
a) True
b) False
Answer: b
Explanation: In the cold-box process, the binder coated sand is allowed in the box and the special gases are passed through it to harden the sand. The gases are passed through it are at normal temperature.
6. Which of the following gases is not used in the cold-box process?
a) Amine gas
b) Sulphur-di-oxide
c) Carbon-di-oxide
d) Marsh Gas
Answer: d
Explanation: Amine gas and sulphur-di-oxide gases are used at high temperatures where the core boxes are made of wood and plastic. The carbon-di-oxide gas is used as a casting core binder in sodium silicate. Marsh gas does not find any applications in the cold-box process.
7. To produce core at room temperature, special binders and air-set sands are used.
a) True
b) False
Answer: a
Explanation: The air-set sands are used to produce cores at room temperature. The sands do not require the gas catalyst because the curing catalyst and organic binders are mixed together already in the sand that initiates the curing process at room temperature.
8. Baking is required for the cores produced by the shell core making method.
a) True
b) False
Answer: b
Explanation: The resin used in the shell core making is allowed to melt to the specified thickness and is cured. The excess sand is dumped or removed. The hardened sand is extracted from the core. This hardened sand is good enough to perform its function and extra baking is not required.
This set of Foundry Interview Questions and Answers for Experienced people focuses on “Principles of Gating and Risering”.
1. When the gases are trapped in the box, they are not allowed to escape.
a) True
b) False
Answer: b
Explanation: When the molten metal poured into the box, it starts to solidify. It results in the emission of certain kinds of gases which may cause a defect in the casting. Thus is gating and the risering system is provided with vent holes to let out these gases.
2. Which of the following is not a component of the gating system?
a) Pouring cups
b) Sprue
c) Pattern
d) Runners
Answer: c
Explanation: The term gating system refers to all the passageways through which the molten metal passes to enter the mould cavity. Pouring cups, sprue and runners make such passage ways. The pattern is the replica of the component to be obtained is not a part of it.
3. If the gating system is part of the pattern, it avoids cutting a runner and gates.
a) True
b) False
Answer: a
Explanation: If the pattern has embedded gating system, its cost reduces considerably and the sand can be rammed harder. It helps to prevent erosion and washing away from the sand as the molten metal flows into the mold.
4. A gating system can allow sudden or right angles.
a) True
b) False
Answer: b
Explanation: Since the way in which the liquid metal enters the mold has a decided influence upon the quality and soundness of casting, the different passages for the molten metal are carefully designed and produced. Hence the sudden change is direction is not allowed.
5. ____________ is responsible for the prevention of erosion and washing away from the sand.
a) Risers
b) Gates
c) Vents
d) Sprue Hole
Answer: b
Explanation: Sudden change in direction causes mold erosion due to mold erosion, turbulence and gas pick-up. So Gates are provided to prevent this erosion and washing away of the sand as molten metal flows into the mould.
6.______________ is also called as the feeder head.
a) Pouring basin
b) Chills
c) Riser
d) Gate
Answer: c
Explanation: A riser is also called as the feeder head is a passage of sand made in the cope during the ramming in the cope. The molten metal rises in the feeder head after the mold cavity is filled up.
7. __________ vacuum in the riser leads to a shrinkage void.
a) Complete
b) Half
c) Partial
d) Approximately full
Answer: c
Explanation: Metals and their alloys shrink as they cool and solidify. It creates a partial vacuum within the castings. Partial vacuum within the casting leads to a shrinkage void. This shrinkage void will grow and form shrinkage cavity if extra liquid metal from outside the mould is not supplied.
8. A riser permits the escape of the air and mold gases.
a) True
b) False
Answer: a
Explanation: Risers promote single directional solidification. When it is full it indicates that the mould cavity is full. A riser permits the escape of air and mold gases as the cavity is being filled with the molten metal.
9. Which is the most common defect caused by the risers?
a) Blow holes
b) Shrinkage
c) Crush
d) Mould Shift
Answer: b
Explanation: The primary function of the riser is to feed metal to the solidifying casting so that shrinkage cavities are get rid of. Hence it can be seen that the common defect is shrinkage which has to be avoided.
10. The metal in the feeder head cannot be compensated to the shrinkage as the casting solidifies.
a) True
b) False
Answer: b
Explanation: The molten metal rises in the feeder head after the mold cavity is filled up. This metal in the feeder hear always compensates the shrinkage as the casting solidifies.
This set of Foundry Multiple Choice Questions & Answers focuses on “Types of Gates”.
1. Which of the following is not an example for the gates?
a) Top
b) Bottom
c) Parting line side
d) Blind
Answer: a
Explanation: A gate is a pathway that connects mould cavity to runners so that the molten metal reaches the mould cavity. Top, bottom and parting line side are all the type of gates but the Blind type is a riser which elevates the excess molten metal.
2. A drop gate is another name for the top gate.
a) True
b) False
Answer: a
Explanation: A top gate is sometimes also called the Drop gate because the molten metal just drops on the sand in the bottom of the mould.
3. ________________ avoids the forceful impinging action of the molten metal stream into the mould cavity.
a) Top gate
b) Edge gate
c) Finger gate
d) Ring gate
Answer: b
Explanation: In an edge gate, a stream of liquid metal impinges against the bottom of the mould cavity until a pool is formed. It avoids the forceful impinging action of the molten metal stream into mould cavity.
4. __________ is used on stove plates castings and bath.
a) Ring gates
b) Finger gate
c) Pencil gate
d) Wedge gate
Answer: d
Explanation: Wedge gates are used on stove plate castings and bath as they are arranged in series and deliver metal rapidly from an elongated pouring basin. They help in keeping the slag back.
5. Finger gate is a modification of wedge gate.
a) True
b) False
Answer: a
Explanation: Wedge gates are in series and the delivery of the molten metal occurs rapidly as the metal is delivered. This process takes time without an elongated basin and hence its modification is done and the finger gate was designed.
6. Which of the following is not an example of the top gate?
a) Finger gate
b) Wedge gate
c) Horn gate
d) Ring gate
Answer: c
Explanation: Top gate is the one in which the molten metal always drops to the bottom of the mould. Hence, finger gate, wedge gate and a ring gate perform such function whereas the horn gate is a bottom gate.
7. Which of the following gates has the lowest consumption of the metal?
a) Top gates
b) Bottom gates
c) Parting line gates
d) All of the mentioned
Answer: a
Explanation: A top gate basin preferably is provided to act as a reservoir or store for molten metal. Due to its simplicity for molding, it has the lowest consumption of the additional metal.
8. Gate with a strainer core is a bottom gate type.
a) True
b) False
Answer: b
Explanation: A strainer core has the functions of filtering the liquid metal if impurities, trapping the slag and to reduce the mould erosion. These are the functions of the parting line side gate. Hence, it cannot be a bottom gate type.
9. Choke is provided to the gate with skim bob and choke.
a) True
b) False
Answer: a
Explanation: A choke is a restriction which controls the rate of liquid metal flow. It prevents the molten metal to enter the mould in the form of a jet and thus minimizes sand erosion. Hence, in a gate with skim bob and choke a choke is provided a choke in between in-gate.
10. Which of the following gates ensures cleaner castings?
a) Edge gate
b) Branch gate
c) Strainer gate
d) Horn gate
Answer: b
Explanation: Slag and liquid metal flow in the runner and rise up in the riser in the branch gate. Thus all the slag goes to the top portion of the riser. Because of all the in-gates, the clean liquid metal enters the mould cavity and produces sound castings.
This set of Foundry online quiz focuses on “Types of Risers”.
1. _________ is exposed to atmosphere in open riser.
a) Top end
b) Bottom end
c) Partial upper end
d) Partial bottom end
Answer: a
Explanation: The open riser is the one in which the full riser indicates that the mould cavity has already been completely filled up with the same. It happens because the top end is exposed to the atmosphere.
2. ______________ is the only feeder force in the open riser.
a) Centrifugal force
b) Gravitation force
c) Centripetal force
d) Compression force
Answer: b
Explanation: The liquid metal in the open riser is fed to the solidifying casting under the force of gravity and the atmospheric pressure till the top surface of the riser solidifies and thereafter it is observed that the gravity is only feeder force.
3. The shape of the open riser is _________
a) Circular
b) Cylindrical
c) Cubical
d) Rectangular
Answer: b
Explanation: In a open riser, the top of the riser was exposed to the atmosphere. An open riser is connected either at the top of the cope or on the side at the parting line. Hence, the shape of the open riser is cylindrical to facilitate these connections.
4. An open riser is easy to mould as compared to a blind riser.
a) True
b) False
Answer: a
Explanation: An open riser is open to atmosphere, thus it ensures that unlike a blind riser it will not draw metal from the casting as a result of partial vacuum in the riser. Hence, it is easier to mould compared to a blind riser.
5. An open riser is difficult to remove compared to a blind riser.
a) True
b) False
Answer: a
Explanation: A blind riser is smaller in size than an open riser. They can be placed at any position but the open riser cannot be placed in the drag. It is generally larger than the blind riser. Hence, it is difficult to remove.
6. The cavity of the blind riser is ______________
a) Square
b) Desired shape
c) Round
d) Rhombus
Answer: c
Explanation: A blind riser is a rounded cavity and it represents the minimum practical ratio of the surface area to the volume and thus associates a slow cooling rate. It is more efficient to use a round shaped blind riser.
7. When a blind riser is used in making of casting, the molten metal cools ________________
a) Rapidly
b) Moderately
c) Slowly
d) Quickly
Answer: c
Explanation: The blind riser is surrounded by sand from all the sides in order to be used in the casting. Due to the presence of this sand the metal in the riser cools slowly. The cooling also depends on the type of metal used.
8. A blind riser can be placed only in specific positions.
a) True
b) False
Answer: b
Explanation: The size of the blind riser is smaller than that of the open riser. It is possible to vary the shape as well and hence they can be placed at any position in the mould.
9. Blind risers promote directional solidification better than the open risering.
a) True
b) False
Answer: a
Explanation: The height of the riser is determined not by the feeding requirements but by the depth of the molding box used. In the case of blind riser these aspects could be varied so it has better solidification than open risering. A blind riser will draw directional solidification from liquid metal from the solidifying casting.
10. The blind risers are connected at top of the cope.
a) True
b) False
Answer: a
Explanation: The blind risers are usually round in shape. It has a minimum practical ratio and hence they are either connected at the top of the cope or on the side of the casting at the parting line or in the drag.
This set of Foundry test focuses on “Fettling and Cleaning of Castings”.
1. _________ is the name given to the removal of cores from the casting.
a) Fettling
b) Pouring
c) Molding
d) Machining
Answer: a
Explanation: Fettling is the name of the process to cover all those operations which help to give the casting a good appearance after the casting has been shaken on a vibrator and then taken out of the sand mould.
2. __________ portions sticking out of inside the castings are removed by poking and action of the metal rod.
a) Pattern
b) Cores
c) Sand
d) Gates
Answer: c
Explanation: It may be difficult to remove dry sand and hardened cores in the absence of suitable equipment. Hammering or vibrations imparted to the cores does not loosen and break them up. Hence they are removed by poking action using a metal rod.
3. Steel castings require considerable more cleaning than those of iron and brass.
a) True
b) False
Answer: a
Explanation: Steel castings, because of their high melting and pouring temperatures and consequent burning of the sand in contact with the molten metal, the possibility of forming of the scales is high. Hence they require more cleaning.
4. _____________ is used for removing adhering sand from the castings.
a) Rumbling
b) Air blasting
c) Wire brush
d) All of the mentioned
Answer: d
Explanation: Rumbling or Trumbling employs a barrel which is rotated at a certain speed and the castings are put and the sand is removed. Air blasting is a method in which air is supplied at a high speed to remove the sand. Wire brush does the same operation. Hence all the above are used to remove the sand.
5. Wire brush is used for non-ferrous production.
a) True
b) False
Answer: a
Explanation: A wire brush consists of hardened steel wires embedded in a block of wood. The materials on which it can be used as grey cast iron, malleable cast iron, steel castings etc where normal clean strip is sufficient and full cleaning operation may be avoided.
6. ______________ is used as an abrasive in the shot blasting method.
a) Zircon
b) Coal tar
c) Chilled iron grit
d) Molasses
Answer: c
Explanation: Chilled iron grit or grit is made by crushing shot. It has irregular sharp edges which act as thousands of tiny chisels and produce more of the scrubbing action than shots in a shot blasting method.
7. ____________ force is responsible for cleaning in mechanical blast method.
a) Gravitation force
b) Tensile force
c) Centrifugal force
d) Shear force
Answer: c
Explanation: The centrifugal force aid in issuing a stream of abrasive particles which impinges on castings being trumbled on an apron conveyor. Due to this high speed action of the centrifugal impellers, the particles are cleaned.
8. ____________ involves a danger of retaining acid in small interstices of castings.
a) Shot blasting method
b) Pickling
c) Hydrolysis
d) Hydro blasting
Answer: b
Explanation: Pickling is one of the methods used in chemical cleaning of the castings manufactured. Pickling makes use of dilute acids for removing sand from the surface and inaccessible pockets of the castings. Hence, there is a danger of retaining a little amount of acid.
9. ____________ castings are pickled in hydrofluoric acids.
a) Iron
b) Brass
c) Steel
d) Aluminum
Answer: a
Explanation: Iron that is the ferrous castings are pickled in hydrofluoric acid . Hydrofluoric acids attack sand on the castings and hence the cleansing becomes easy.
10. Automatic shot blasting plants are capable of high production rates.
a) True
b) False
Answer: a
Explanation: The automatic shot blasting process is a continuous shot blast cleaning operation can be approached by skip loading and by dual turntable plants so that loading and unloading of the castings can take place outside the work chamber when the blasting is going on. Hence, it can be used for a high production rate.
This set of Foundry Multiple Choice Questions & Answers focuses on “Casting Defects”.
1. ______________ is a defect caused by loose dowels.
a) Mould Shift
b) Scab
c) Drop
d) Blow holes
Answer: a
Explanation: Mould shift produces a casting which does not match at the parting line. There is mismatching of the top and bottom parts of the casting at the mould joint due to worn out, loose, bent or ill-fitting of the clamping pins.
2. Variation in wall thickness occurs due to _________ core boxes.
a) Rigid
b) Flexible
c) Surface finished
d) Worn out
Answer: d
Explanation: Worn out core boxes give oversize core dimensions. Worn out core prints allowing a core to float or move. Inadequate core print areas permit lifting of the core due to the buoyancy of molten metal. Hence the variation in wall thickness occurs.
3. __________ usually occurs at the parting line and results in excess of metal.
a) Fins
b) Fash
c) Strain
d) All of the mentioned
Answer: d
Explanation: The fins, fash and strain all occur due to the same reason. They occur at the parting line. Straining or movement of the mould makes a casting appreciably thicker than the pattern. Hence, at the parting line excess metal is accumulated which is to be grounded off.
4. Patterns having insufficient taper result in __________
a) Fins
b) Blow holes
c) Drop
d) Scab
Answer: a
Explanation: Fins at the mold joint occur when bottom boards are too flexible or if the pattern plates are not sufficiently rigid to keep straight during ramming. Thus the pattern having insufficient taper require excessive rapping for the withdrawal from sand which results in fins at joint.
5. _______________ occurs in the casting due to the quality variation.
a) Defects
b) Melting
c) Stress-reliving
d) Solidification
Answer: a
Explanation: Under normal conditions, like all the metallurgical products, castings also contain certain imperfections which contribute to a normal quality variation. Such imperfections are taken as defects or flaws.
6. Defective casting account normally for the higher losses than any other losses incurred by foundry industry.
a) True
b) False
Answer: b
Explanation: The defects such as blowholes, scab etc result in degenerated castings which make them unsuitable to perform the functions they are supposed to perform. That makes the entire casting to be scrapped off. Hence, it is the greatest loss to the industry.
7. Defects by ____________ are discovered by mechanical testing.
a) Heat-treatment
b) Molding
c) Material
d) Pattern
Answer: c
Explanation: The material used for the making of the castings has several mechanical properties such as tensile strength, compressive strength etc which are expected in the castings. These material defects are defects in mechanical properties of the casting.
8. Surface defects are discovered by radiography.
a) True
b) False
Answer: b
Explanation: The defects in the castings which exist under the surface are not able to be discovered by conventional methods. Hence they are revealed by processes such as machining, sectioning or radiography.
9. The best defense against the defects in castings is visual examination and machining.
a) True
b) False
Answer: b
Explanation: Visual examination and machining take time for the dispatch of the manufactured castings. Instead, close control and standardization of all the aspects of manufacturing technique offer the best defense against the occurrence of defects in castings.
10. ________________ is the displacement of the mould while closing a mould.
a) Drop
b) Blowholes
c) Crush
d) Mould Shift
Answer: c
Explanation: A crush allows itself as an irregular sandy depression in the casting. It occurs due to an excessive weighting of the green sand mould. Hence, it is the displacement of sand while closing a mold, thereby deforming mold surfaces.
This set of Foundry Multiple Choice Questions & Answers focuses on “Moulding Machines”.
1. ______________ machine is used to ram sand in the mould box.
a) Jolt Machine
b) Sand Slinger
c) Core making machine
d) Squeezing machine
Answer: b
Explanation: Sand slinger is a machine which has a rapid rotating cup shaped blade that picks up the sand and throws it downward into the molding sand and throws it downwards with a great force and thus it rams the sand in the mould box.
2. In the sand slinger machine, the density of sand is a result of its ___________
a) Inertia
b) Acceleration
c) Velocity
d) Mass
Answer: a
Explanation: While the sand is rammed in the molding boxes using a sand slinger, sand is filled and rammed at the same time. The density of sand is the result of sand’s inertia which is uniform throughout the mould.
3. _________ machines are used for shallow patterns.
a) Core making machine
b) Sand Slinger machine
c) Squeeze machine
d) Jolt machine
Answer: c
Explanation: A squeezer, squeeze head plate or presser board slides inside the flask to compress the sand above and around the pattern. The presser plate exerts a substantial amount of pressure. The pressure can be easily distributed for the shallow patterns in a squeeze machine.
4. Which of the following mediums is not used for the power operated molding machines?
a) Electromagnets
b) Hydraulic power
c) Compressed air
d) Sand Inertia
Answer: d
Explanation: The power operated molding machines are extension versions designed to overcome all the drawbacks of molding occurred by the traditional machines. The sand inertia is used for molding and is not a medium of machine whereas, the use of compressed air, hydraulic power or high impellor is used to obtain performance from power operated machines.
5. In a squeeze molding machine, the sand is rammed of the mould edge as well.
a) True
b) False
Answer: a
Explanation: The squeeze molding machine rams the sand harder at the back of the mold and softer on the pattern face. Sand has the greatest density at the surface where a pressure is applied to sand. In modern machines, the harder ramming on the mould edge is also ensured.
6. ___________ is used to obtain a uniform mold density in squeezer machine.
a) Sand paper
b) Flat plate
c) Rubber
d) Carbon
Answer: c
Explanation: In the squeezer machine, squeezing a flat plate produces non-uniform sand density and mold softness, whereas rubber diaphragm squeezing distributes squeeze molding forces more uniformly and thus a uniform mold density is obtained.
7. Which of the following is not a power operated machine?
a) Jolt machine
b) Sand Slinger
c) Pin lift machine
d) Jolt squeeze machine
Answer: c
Explanation: The pin lift machine is a hand molding machine. The operations and withdrawing of the pattern from the mould in the hand molding machine is accomplished mechanically which is the working phenomenon if pin lift machine.
8. The pattern equipment associated with the molding machines possesses longer life.
a) True
b) False
Answer: a
Explanation: All the castings produces using molding machines possesses correct and same size, shape, since no hand rapping is required to extract the pattern from the mold. Due to this, the pattern equipment has longer life.
9. Molding machine equipment is not as flexible as hand molding.
a) True
b) False
Answer: a
Explanation: Molding machine equipment is costlier than hand molding. Molding machine cannot be used for large and complex shapes. For the manufacturing of the large castings, hand molding process is to be employed.
10. ____________ establishes the most suitable gating system, riser etc are mounted on the match plate pattern itself.
a) Machine molding
b) Hand molding
c) Sand molding
d) Core molding
Answer: a
Explanation: Molding machines have patterns fixed on them which have inbuilt gating system and runner, gate etc that are mounted on the match plate itself. They perform their action rapidly and more accurately than the other types of molding.
This set of Foundry Multiple Choice Questions & Answers focuses on “Green Sand Moulding”.
1. In green sand molding, the sand id claimed to be green because it has _______
a) Additives
b) Moisture
c) Binders
d) Colours
Answer: b
Explanation: In foundry processes, the sands are called green due to the moisture content in them. The moisture content makes the sand wet which is suitable for the molding. The moisture content varies according to the type of casting to be made.
2. The sand has to undergo ____________ process before it is called green and is ready for molding.
a) Mulling
b) Cooling
c) Heating
d) Drying
Answer: a
Explanation: The green sand, before being called green has to undergo a process called mulling process in which the clay, binders and various additives are blended together to make it suitable for its usage.
3. Which of the following is not used in the green sand?
a) Clay
b) Water
c) Oil
d) Chemicals
Answer: c
Explanation: In the making of the green sand, clay is present in the form of bentonite. Water percentage is varied as required for a particular casting. Oil is not the kind of binder used in the green sand. Bentonite is the only binder used.
4. Green sand molding cannot be used for _________ moulds.
a) Simple
b) Small
c) Medium
d) Complex
Answer: d
Explanation: In green sand molding, the metal is poured in them in wet condition. It is easy to mould the wet sand with hand only for small to medium sized moulds which make it difficult to use the green sand molding for the production of the complex castings.
5. Green sand is widely used for hand molding purposes.
a) True
b) False
Answer: a
Explanation: The green sand is a mixture of silica sand with 15-25 percent clay and 6-8 percent water. Being damp the sand can be easily worked with hand to give it only desired shape due to its easy mold ability.
6. Green sand molding methods can be used for ________ molding machines.
a) Manual
b) Semi-automatic
c) Fully automatic
d) All of the mentioned
Answer: d
Explanation: The green sand molding method involves highly moldable sand which ensures flexibility of the castings that could be prepared using this method. It is flexible to be used in all the machines.
7. Which of the following characteristic is not expected in the green sand in the green sand molding process?
a) Flowable nature
b) Plastic Nature
c) Reactivity
d) Permeability
Answer: c
Explanation: If the green sand develops the quality of reactivity in it, it will have significant defects in it which will result in discarding of the entire casting. Hence all the qualities except reactivity are desired in the sand.
8. Green sand molding is replacing the costlier molding processes as the sand control methods are being applied.
a) True
b) False
Answer: a
Explanation: In green sand molding, proper attention can be given on the content of sand, range of the moisture, additives and binder content etc. Sand control methods are established and so it has an edge over the other molding methods.
9. Green sand must exhibit high refractoriness in the green sand molding.
a) True
b) False
Answer: a
Explanation: Green sand must guarantee good refractoriness to withstand the high temperature which is generated due to the molten metal and it should not be involved in any kind of melting or fusing with the metal.
10. Green sand does not require dry strength.
a) True
b) False
Answer: b
Explanation: Dry strength refers to the strength of the sand when the surface dries out. Green sand is also required to have adequate dry strength when it is to be used in the green sand molding in order to prevent the erosion of the liquid metal during pouring as the mould surface dries out.
This set of Foundry Quiz focuses on “Core and Shell Moulding”.
1. _____________ is well known as the expendable molding process.
a) Core molding
b) Hand molding
c) Machine molding
d) Shell molding
Answer: d
Explanation: Shell molding uses a resin which is covered in sand to form a mold. This mold casting involves the use of non-reusable or temporary sand depending upon the casting to be made. Hence, it is known as expendable mould.
2. The patterns can be __________ after the pattern is prepared from shell molding.
a) Scrapped
b) Non-reused
c) Reused
d) Recycled
Answer: c
Explanation: The pattern is placed in a mould in shell casting is a thin-walled shell which is created using a sand resin and applying it all over the pattern. This makes the pattern to be easily reusable for the next subsequent processes.
3. Shell molding has better dimensional accuracy than any other casting process.
a) True
b) False
Answer: a
Explanation: Shell molding is conducted using an expendable mold. As it includes sand, plastic and investment moulds, the dimensional accuracy obtained from this sand casting. It is used for small to medium parts.
4. Which of the following is not used in the shell molding?
a) Metal Pattern
b) Sand-resin
c) Dump box
d) Gating system
Answer: d
Explanation: In a shell molding process, the pattern is incorporated with the gating system as it has to be coated with the required sand resin before the process begins. It does not require the gating system separately.
5. Which of the following cannot be made from the shell molding process?
a) Cylinder heads
b) Connecting rods
c) Engine blocks
d) Valves
Answer: d
Explanation: The valves are prepared using a pressure die casting process or it is done by a green sand molding process. It does not require high work to be done on pattern making which is done in the shell molding process.
6. The lead times in Shell molding is usually _____________
a) High
b) Rapid
c) Short
d) Medium
Answer: c
Explanation: The lead time refers to the time between the loading and unloading of the component before and after finishing respectively. As the process is automated in the shell molding, the lead time required is short.
7. The binder used in the shell mold casting process is ___________
a) Thermoplastic
b) Thermosetting
c) Plastic
d) Elastic
Answer: b
Explanation: The shell mold casting process uses the thermosetting binder so that they can harden the thin shell of sand when they are baked. They prepare the sand with the properties required for the processes.
8. The typical parts like cylinder heads, gears and bushings are produced using the shell molding process.
a) True
b) False
Answer: a
Explanation: The shell molding process is suitable for the castings which are low in weight. Usually, they weigh around 20 lbs. As these components are of low weight they are manufactured by the shell molding process.
9. ________________ facilitates the removal of the shell.
a) Dextrin
b) Sand
c) Zircon
d) Silicone
Answer: d
Explanation: In the shell molding process, the pattern is coated with sand and typical binders and a shell are created over it. After the shell is done, a parting agent is coated over it to facilitate the easy removal of the shell. Silicone is a parting agent.
10. The thickness of the shell is dependent upon the strength required for the mold for the specific metal casting application.
a) True
b) False
Answer: a
Explanation: The reaction of the thermosetting resin with hot metal pattern forms the thin shell on the surface of the pattern. The thickness of the mold can be controlled by the length of the time the sand mixture is in contact with the pattern.
This set of Foundry Multiple Choice Questions & Answers focuses on “Gravity Die Casting”.
1. Blowing of air is required in water passages is gravity die casting.
a) True
b) False
Answer: b
Explanation: Water is sometimes used as a cooling agent in the gravity die casting process. Water passages in the mould or cooling fins made on the outside of the mould surface are blown by air otherwise water mist is created in the chilling effect.
2. Cores in permanent moulds used in gravity die casting are made up of ___________
a) Metals
b) Metal and Non-metals
c) Metals and sand
d) Only sand
Answer: c
Explanation: Metal cores are used when they can be easily extracted from the casting whereas a dry sand core or a shell core is preferred when the cavity is to core is such that a metal core cannot be possibly withdrawn from casting. Hence, metal and sand are employed.
3. A chill is used to promote directional solidification in gravity die casting.
a) True
b) False
Answer: a
Explanation: Chills are pieces of copper, brass or aluminum and are inserted into the mould’s inner surface. The chill is a component used to promote solidification in a specific portion of a metal casting mould.
4. The mold halves are clamped by ________ in gravity die casting.
a) Lathes
b) Pneumatic
c) Toggles
d) Lathes, Pneumatic and Toggles
Answer: d
Explanation: In a gravity die casting, the two mould halves present are securely clamped before the pouring operation takes place. Simple mechanical clamps are adequate for small moulds where as larger permanent moulds need pneumatics or power clamping methods.
5. For faster cooling, fins are provided __________ the permanent mould.
a) Inside
b) Outside
c) At the surface
d) Near the end
Answer: b
Explanation: The pouring cup, sprue, gates and the risers are built inside the mold halves itself. The fins and other projections are provided on the outside of the permanent mould as they ensure faster cooling of the casting.
6. In gravity die casting, __________ the thickness of the mold walls, greater the amount of heat removal.
a) Lesser
b) Equal
c) Greater
d) Negligible
Answer: c
Explanation: The greater thickness of the mold walls can remove greater amounts of heat from the casting, they that is the mould walls are made thicker opposite thicker sections of the castings. This provides a desirable chilling effect.
7. The thickness of the permanent mould is _______
a) High
b) Low
c) Negligible
d) Moderate
Answer: d
Explanation: The permanent moulds are made of dense, fine grained, heat resistant cast iron, steel, bronze, anodized aluminum, graphite or other suitable refractories. The thickness is moderate to around 15-50 mm are higher dimensions are avoided.
8. A permanent mould is made up of two halves.
a) True
b) False
Answer: a
Explanation: The permanent mould is made in two halves in order to facilitate the removal of the casting from the mould. It may be designed with a vertical parting line or with a horizontal parting line.
9. Molten metal is poured into the mould due to the effect of gravity with _______ external pressure in gravity die casting.
a) High
b) Low
c) Medium
d) No
Answer: d
Explanation: Molten metal is poured into the mould under gravity only; no external pressure is applied to the force the liquid metal into the mold cavity. However, the liquid metal solidifies under pressure of metal in risers.
10. Gravity die casting makes use of a permanent mould.
a) True
b) False
Answer: a
Explanation: A gravity die or a permanent mould casting makes use of a mould which is permanent that is the mould can be reused many times before it is reused or rebuilt.
This set of Foundry Assessment Questions and Answers focuses on “Pressure Die Casting”.
1. The pressure is obtained by which of the following methods in pressure die castings?
a) Mechanical
b) Hydraulic
c) Pneumatic
d) Electromagnetic
Answer: b
Explanation: In the pressure die casting process, the molten metal is forced into the permanent mold or dies cavity under pressure. The requirement for pressure is high. The pressure is generally obtained by compressed air or by hydraulic methods.
2. Gooseneck injection type mechanism is ___________ chamber mechanism.
a) Hot
b) Cold
c) Temperature Independent
d) Room temperature
Answer: a
Explanation: The Gooseneck or the air injection type process utilizes air at relatively high pressures. The pressure if the air is around 30 to 40 kg/cm². As the molten metal is also present beneath the surface it is a hot chamber process.
3. The pressure is maintained in the mould till the casting is solidified.
a) True
b) False
Answer: a
Explanation: The entire pressure die casting process when required to produce castings of certain types, requires the same pressure to be retained till the end of the solidification process. This pressure has to be maintained to obtained good quality castings.
4. The Gooseneck mechanism is more efficient than the plunger mechanism.
a) True
b) False
Answer: b
Explanation: The compressed air is used in gooseneck mechanism and this compressed air does not produce pressure on molten metal as effectively as the plunger does. Hence the plunger is more effective.
5. In hot chamber machine, the melting unit constitutes and integral part.
a) True
b) False
Answer: a
Explanation: Depending on the size, hot chamber die-casting machine produces the components. The molten metal possess normal amount of superheat and, therefore, less pressure is needed to force the liquid metal into the die. This is easier because the melting unit is an integral part.
6. Air injection processes can be used for __________
a) Iron
b) Scandium
c) Zinc
d) Argon
Answer: c
Explanation: The air injection type of hot chamber die casting machine can produce castings of low melting point metals such as zinc, tin and lead etc.
7. __________ are useful in cold chamber machines.
a) Riser
b) Gates
c) Ladles
d) Shell
Answer: c
Explanation: The melting unit is not an integral part of the cold chamber die casting machine. Molten metal is brought and poured into the die-casting machine with the help of the ladles that carry this molten metal.
8. ______________ pressure is recommended in the cold chamber process.
a) High
b) Low
c) Medium
d) Room temperature
Answer: a
Explanation: The pressure required to force metal into the die of the cold chamber die casting process is of the order of 200 to 2000 kg/cm² and hence high squeezing action is exerted on the metal while it solidifies.
9. Low melting point alloys can be cast in the cold chamber pressure die casting.
a) True
b) False
Answer: b
Explanation: Cold chamber die casting machines are chiefly used for making castings in aluminum, brass and magnesium. Though the low melting point alloys also can be cast, but they are more economically done so in fast operating hot-chamber machines.
10. Pressure die casting is used for high volume production because ____________
a) High maintenance
b) Costly machinery
c) Complex dies
d) All of the mentioned
Answer: d
Explanation: The pressure die casting process is used only for the processes which require tight tolerances and detailed geometry. For making such dies, the economical aspect is very high and the maintenance of these machines is equally large. Hence they are used only for high-end production.
This set of Basic Foundry Questions and Answers focuses on “Centrifuging Processes”.
1. In centrifugal castings, the molten metal is introduced into a ___________ mould.
a) Rotating
b) Static
c) Swinging
d) Heating
Answer: a
Explanation: The essential feature of centrifugal casting is the introduction of liquid metal into a rotating mould. The force responsible for it is the centrifugal force which plays a major role in shaping and feeding of the casting.
2. True centrifugal castings are __________ in shape.
a) Straight
b) Square
c) Round
d) Rectangular
Answer: a
Explanation: The true centrifugal castings are straight and have uniform inner diameter is produced by spinning the mold about its own axis. It is rotated either vertically or horizontally as needed to do it.
3. The metal is poured in the inner surface of the mold cavity.
a) True
b) False
Answer: b
Explanation: A cylindrical mold is utilized in the true centrifugal casting and is made to rotate on its own axis at such a speed that the metal is poured is thrown to the outer surface of the mould cavity. The metal solidifies to form a hollow cylinder.
4. In the De Lavaud casting process, the coolant used is ___________
a) Water
b) Resin
c) Aerated water
d) Inert gases
Answer: a
Explanation: The De Lavaud process makes use of the metal moulds. The machine contains an accurately machined metal mould , entirely surrounded by the cooling water to keep it cool and to increase the production.
5. The De Lavaud machine is highly locomotive.
a) True
b) False
Answer: a
Explanation: The De Lavaud machine makes use of the metal moulds. This machine is mounted on wheels and it can be moved lengthwise. This is placed on a slightly inclined track to increase flexibility.
6. True centrifugal castings can be prepared in ___________ moulds.
a) Metal
b) Sand
c) Metal and sand
d) Sand and chemical
Answer: c
Explanation: Metal moulds prove to be economical when larger quantities of castings are required to be produced. The true centrifugal castings may be produced in metal or sand lined moulds, depending largely upon the quantity desired.
7. The _____________ parts are cast in centrifuge castings.
a) Symmetrical
b) Asymmetrical
c) Identical
d) Non-Identical
Answer: b
Explanation: Parts not symmetrical about any axis of rotation may be cast in the group of moulds arranged in a circle to balance each other. The axis of mold and that of rotation does not coincide with wach other. The set up is revolved around centre to induce pressure on the metal moulds.
8. There are a lot of limitations on the castings produced by the centrifuge castings.
a) True
b) False
Answer: b
Explanation: In centrifuge castings, the shape of the castings imposes no special limitations in this process and an almost unlimited variety of smaller shapes can be cast using this process.
9. _________ molding is used to produce valve bodies in centrifuge casting.
a) Stack
b) Straight
c) Hand
d) Machine
Answer: a
Explanation: In centrifuge castings, when the castings in multiple layers one above the other are produced in one mould, the method is called stack molding. It is used for producing valves bodies, plugs, yokes etc.
10. High spinning is needed in semi-centrifuge casting.
a) True
b) False
Answer: b
Explanation: Spinning speeds in the semi centrifuge casting need not be as high as those used for true centrifuge castings. A linear speed of the order of 180-200 rpm at the outside edge of the casting is generally recommended.
This set of Foundry Multiple Choice Questions & Answers focuses on “Carbon Dioxide Mould”.
1. The use of CO 2 was to __________ the sand mould.
a) Harden
b) Soften
c) Dry
d) Clean
Answer: a
Explanation: The idea of hardening sand moulds by gassing it with carbon-di-oxide was conceived. However, the CO 2 molding has been adopted for a wide range and scale for modern core making.
2. ________________ is the binder used in the CO 2 moulding.
a) Silica sand
b) Sodium Silicate
c) Sodium Carbonate
d) Alumina
Answer: b
Explanation: The CO 2 moulding is an extremely simple procedure. The highly flow able mixture of pure dry silica and sodium silicate binder is rammed or blown into the mould or cores box. Due to sodium silicates excellent binding properties with silica sand it is used as binders.
3. CO 2 used in CO 2 molding is at high pressure.
a) True
b) False
Answer: b
Explanation: Carbon-dioxide gas is used at a low pressure usually about 1.5 kg/cm 2 is diffused through a mixture to initiate the hardening reaction which takes from a few seconds to a few minutes depending upon the size of the core or mold.
4. If gas is passed longer than required, the bond becomes ____________
a) Impaired
b) Stronger
c) Weaker
d) Does not affect much
Answer: a
Explanation: When the gas is passed at the required pressure, the compression strength of a given sand mixture reaches its maximum at some critical amount of gas passed. If gassing is continued beyond the critical point, the strength of the bond is impaired.
5. Clay is used in the CO 2 molding process.
a) True
b) False
Answer: a
Explanation: The clay is used alongside sodium silicate as a binder. The clay used is usually in small quantities. The clay and starch are added to improve the green strength of the mix prepared.
6. _____________ increases SiO 2 -Na 2 O ratio that increases the bond.
a) Sulphuric acid
b) Acetic acid
c) Carbonic acid
d) Hydrochloric acid
Answer: c
Explanation: Passage of carbon-dioxide through the sand containing sodium silicate produces carbonic acid in the aqueous solution. This causes a rise in the SiO 2 -Na 2 O ratio and formation of a colloidal silica gel, which hardens and forms the bond between sand grains.
7. The additives in sodium silicate are ____________
a) Sugar
b) Dextrin
c) Molasses
d) Zircon
Answer: b
Explanation: The sodium silicate my contain additives such as sugars to help the breakdown of the core in casting that is to improve the collapsibility of the core. Molasses is the by-product of the sugar industry hence it is not used.
8. Overgasing increases the core strength.
a) True
b) False
Answer: b
Explanation: Overgasing usually decreases the strength of the core which is responsible for functioning in the CO 2 molding. It causes the production of the defective castings.
9. Rough patterns are difficult to withdraw from CO 2 molding.
a) True
b) False
Answer: a
Explanation: Since gassing hardens the sand mass, a pattern having a rough surface may become difficult to withdraw from the mould. However, this can be overcome if the pattern has been rubbed with graphite before ramming the sand around it.
10. Short gassing time is highly effective in CO 2 molding.
a) True
b) False
Answer: a
Explanation: Short gassing times have proved to be effective in producing strong cores. The short gassing times increase the efficiency of the cores used in this process.
This set of Foundry Multiple Choice Questions & Answers focuses on “Squeeze Casting”.
1. The squeeze casting can result in an increase of _________ properties of the castings.
a) Thermal
b) Mechanical
c) Thermodynamic
d) Chemical
Answer: b
Explanation: As the material of the casting goes under various variations of temperature, they are able to attain a certain amount of increase in its mechanical properties such as high tensile strength, high bending strength etc.
2. Squeeze casting is used for manufacturing of components of _________
a) Aluminum alloys
b) Iron alloys
c) Chromium alloys
d) Carbon alloys
Answer: b
Explanation: The squeeze casting process can be used to produce both ferrous and non-ferrous metal components with ferrous components having an edge over it. It is mainly used for making of the fiber-reinforced castings from fiber cake perform.
3. Pressure applied in the squeeze casting process is less than that of forging.
a) True
b) False
Answer: a
Explanation: In the squeeze casting process, usually aluminum alloys are used to form a casting. Intricate and detailed parts are prepared using this process. Hence it is not advisable to apply pressure in squeeze casting as it is applied in forging.
4. Pressure incorporated in the direct die casting is _____________
a) High
b) Low
c) Not used
d) Room temperature
Answer: a
Explanation: In direct die casting, the upper segment of the die is always closed to form a casting when the metal is present. A high pressure of 100MPa and more is applied to the entire cavity in order to get the part solidified.
5. Direct squeeze casting process is similar to the forging process.
a) True
b) False
Answer: a
Explanation: In direct squeeze casting, the liquid metal is poured into a lower die segment which is situated in the hydraulic press. This closely resembles the forging process in action.
6. ________ squeeze casting takes place in die casting equipment.
a) Direct
b) Indirect
c) Room temperature
d) None of the mentioned
Answer: c
Explanation: The equipment used for the Indirect squeeze casting can be vertical or horizontal depending upon the design of the casting. As the process is almost similar to that of the die casting the same equipment can also be used for this process.
7. _____________ is the advantage of the squeeze casting process.
a) Weld-able
b) No Blow Holes
c) Heat treatable
d) All of the mentioned
Answer: d
Explanation: Due to the Ultra slow filling and directional solidification, the squeeze casting process provides efficient and highly accurate components avoiding casting defects. This makes the components feasible for treating processes such as Heat treatment, welding, etc.
8. Squeeze casting is a combination of casting and forging.
a) True
b) False
Answer: a
Explanation: Squeeze casting is a process in which the molten metal is subjected to high pressure under which the metal forms into casting. The high pressure application is just like the one in forging. Hence it is the combination of both.
9. Porosities are eliminated in the squeeze die casting process.
a) True
b) False
Answer: a
Explanation: Because of the high pressure which is applied during the solidification process of the metal, the gas finds it easy to escape out. Hence, the porosities caused by the gas as well as the shrinkage can be prevented and eliminated.
10. The cooling rate is increased by applying high pressure in the squeeze die casting process.
a) True
b) False
Answer: a
Explanation: The cooling rate can be increased by applying high pressure during the solidification process. Since the contact between the casting and the die is improved by the pressurization process, which results in the foundation of the fine-grain structures.
This set of Foundry Questions and Answers for Entrance exams focuses on “Gas Fired Pit Furnace”.
1. High atmosphere circulation is attained in a pit furnace.
a) True
b) False
Answer: a
Explanation: The circulation fan is mounted centrally in the lid. The retort is formed as a cylinder with a flange on top. On this flange, there is a circular cooling tube. Thus, highly efficient atmosphere circulation system is present in the Pit furnace.
2. _________ is used for insulation in Pit furnaces.
a) Polymer fiber
b) Ceramic fiber
c) Metal matrix reinforced fiber
d) Plastic fiber
Answer: b
Explanation: The ceramic fiber is lined inside the furnace body. The insulation is provided to save the heat from going out. It acts as an energy saving shield and reduces operation costs.
3. The coke in the pit furnace burns completely.
a) True
b) False
Answer: a
Explanation: The coke bed which is formed in the furnace is ignited and allowed to burn. Once it reaches the state of maximum combustion, coke from the centre of coke bed is shifted towards sides to make space for crucible containing the metal charge.
4. Pit Furnace is used in ___________
a) Permanent mould
b) Shell mould
c) Skin dried mould
d) Air dried mould
Answer: a
Explanation: Pit furnace has a limited capacity. It is used to melt a certain low amount of metal to produce castings. Only small castings can be produced. Hence, it is often used with permanent moulds and die casting machines.
5. Gas Pit furnaces are situated in long heating tubes.
a) True
b) False
Answer: b
Explanation: The furnace is constructed in a pit and it extends to floor level or a level little above the ground. This manner provides efficient loading and minimal distortion.
6. ________ is used to fuel gas furnace.
a) Marsh gas
b) Carbon-dioxide
c) Ammonia gas
d) Natural gas
Answer: d
Explanation: The natural gas is widely available and can be used for the gas furnace due to its easy combustion method. As a gas furnace have a burner in the furnace it is fuelled by natural gas.
7. _____________ is used to accelerate the metal cooling in gas pit furnace.
a) Coolant
b) Fans
c) Blower
d) Cannot be determined
Answer: c
Explanation: The draft of the air through furnace may be a natural draft for low melting temperature metals but this force draft can be used to accelerate the melting process with the help of the blower.
8. Large compositional change occurs in the charge while using the Gas pit furnace.
a) True
b) False
Answer: a
Explanation: Since the molten metal does not come in contact with the fuel, there is no pick up of the elements by the metal from the coke and hence a very little compositional change occurs in the metal charge of the gas pit furnace.
9. The gas pit fire furnace is fired with gun powder.
a) True
b) False
Answer: b
Explanation: The gas pit furnace is fired with coke, oil or gas. For maximum amount of times, it is seen to be fired with coke. Enough coke is packed round so as to melt and superheat the metal charge.
10. The gas fired pit furnace is used for tempering and normalizing.
a) True
b) False
Answer: a
Explanation: The gas fired pit furnace is used for tempering, normalizing and solution treatment which is used in aluminum and in annealing. It is used for such process as it is a standard in various industries for fast heat up and to obtain uniformity in temperature very fast.
This set of Foundry MCQs focuses on “Electric Arc Furnace”.
1. Induction _______ is the principle of Induction furnace
a) Current
b) Heating
c) Resistance
d) Melting
Answer: b
Explanation: The Induction heating is the process by which the passage of an electric current through a conductor releases heat. Hence it is a principle used in Induction furnace.
2. The currents induced in the electromagnetic induction principle for induction furnace is called _____
a) Direct current
b) Indirect current
c) Eddy currents
d) Electric current
Answer: c
Explanation: The energy transfer to the object to be heated occurs by means of electromagnetic induction. Any electrically conductive material placed in a variable magnetic field is the site of induced electric currents, called eddy currents, which will eventually lead to joule heating.
3. Joule heating is called as resistive heating.
a) True
b) False
Answer: a
Explanation: The heat which is produced in the joule heating is directly proportional to the square of the current multiplied by the electrical resistance of the wire used. Hence, joule heating is termed as resistive heating or ohmic heating.
4. Induction heating in Induction furnace relies on ______________ frequency.
a) Radio
b) X-Rays
c) Infrared
d) Ultrasonic
Answer: a
Explanation: Induction heating relies on radio frequency as it is a part of electromagnetic wave that portion of electromagnetic spectrum below infrared and microwave energy. Since heat is transferred to the product via electromagnetic wave, it never comes in direct contact with any flame, the indicator doesn’t get hot and there is no product contamination.
5. Induction furnace usage has the highest refining capacity.
a) True
b) False
Answer: b
Explanation: Induction furnace has a lack of refining capacity; the charge materials must be clean of oxidation products and of oxidation products and of known composition, some alloying elements are lost due to oxidation.
6. The crucible inside the furnace is cooled by __________
a) Coolant
b) Air
c) Water
d) Gas
Answer: c
Explanation: The crucible in which the metal is placed is made of stronger materials that can resist the required heat, and the electric coil itself cooled by a water system so that it does not overheat or melt. The induction coil is cool to touch but the heat that builds is to be cooled.
7. Which of the following furnaces is the best to melt scrap?
a) Cupola
b) Electric arc
c) Induction
d) Blast
Answer: c
Explanation: The induction furnace is commonly used to melt all grades of steels and iron as well as many non-ferrous alloys. As it can be used for re-melting of the metals, it is suitable for melting of scrap and reusing it.
8. The induction furnace can be used to melt as well as re-melting of the metal.
a) True
b) False
Answer: a
Explanation: The furnace is ideal for the melting and re-melting and alloying because of the high degree of control over the temperature and chemistry while the induction current provides good circulation of the molten metal.
9. Coreless Induction Furnace operates on ___________
a) Transformer
b) Induction motor
c) Generator
d) Motor
Answer: a
Explanation: Coreless induction furnace consists of two types of coils; primary and secondary coil. The wall of the container forms the secondary winding and the iron core links the primary as well as the secondary coil. This is the principle of the transformer as well as induction furnace.
10. The induction furnace is replacing cupolas in the foundries.
a) True
b) False
Answer: a
Explanation: The induction furnace ranges from sizes of a small furnace to big one depending upon the amount of weight which is to be melted and the size of the organization. It is also replacing cupolas it emits lots of dust and pollutants and is less flexible in operations than induction furnace.
This set of Foundry Multiple Choice Questions & Answers focuses on “Cupola Furnace”.
1. Cupola is the best example for __________ furnace.
a) Top open
b) Bottom open
c) Left open
d) Right open
Answer: b
Explanation: In the cupola, after the melting operation is done, the bottom doors swing out of the way and thus the contents of cupola drop down through the opening . Hence, the cupola furnace is the best example for the bottom open furnace.
2. Air is supplied to cupola using ___________
a) Blowers
b) Coolers
c) Tuyeres
d) None of the mentioned
Answer: a
Explanation: The Tuyeres are the components in the cupola that extend through the steel shell and refractory wall to the combustion zone and supply air necessary for the combustion. Hence, the wind box that surrounds the cupola supplies the air evenly to all the tuyeres.
3. Cupola uses low grade coal as fuel.
a) True
b) False
Answer: b
Explanation: The fuel that is used for cupola is generally a very high grade low-sulphur coke, anthracite coal or carbon briquettes. These fuels produce a large amount of smoke when used for combustion but produce the amount of heat required for working of the cupola.
4. The ratio of iron to coke fed in cupola is ___________
a) 6:10
b) 1:10
c) 10:1
d) 12:16
Answer: d
Explanation: The coke has excellent burning properties and can be used to melt iron easily. Coke is always supplied in low quantities so that it can produce enough heat to melt the iron and the pollution making factor for the coke is relatively less.
5. Cupola can produce the metal of uniform quality.
a) True
b) False
Answer: b
Explanation: The cupola can be made up of different sizes. The amount of metal given for melting is non-uniform. Usually, scrap is melted in a cupola. Scrap being of the non-uniform grade produces a metal of non-uniform quality.
6. _________ tuyeres increase the melting efficiency.
a) Single
b) Double
c) Auxiliary
d) Blast
Answer: c
Explanation: The tuyeres are responsible for the supply of air for combustion in the cupola. The tuyeres are always fitted in one or more number of rows. Auxiliary tuyeres being more efficient are fitted in the cupola to supply more air and increase melting efficiency.
7. The cupola has following as waste ____________
a) Slag
b) Iron
c) Coke
d) Slag, Iron and Coke
Answer: d
Explanation: After the melted iron is removed from the cupola, the contents of the cupola that is the unburned coke, slag and partially melted iron is removed and dumped. The material such as slag, iron and coke sticking to the side walls is chipped off.
8. The refractory material is sticked inside the steel vessel using _______________
a) Binders
b) Blowers
c) Additives
d) Manual work
Answer: b
Explanation: Once the eroded material is removed, the eroded refractory lining at the combustion zone is filled with the pneumatically operated gun which blows refractory patching mixture at sufficient velocity so that it sticks properly to the lining.
9. The air supplied to the cupola in measured quantities.
a) True
b) False
Answer: a
Explanation: In cupola, the amount of iron input for melting is dependent on the size and the air required for combustion depends on the amount of metal. Usually, a track of supplied air is kept using the volume meter which measures the air supplied in the combustion chamber.
10. The damaged patch of the cupola can be repaired.
a) True
b) False
Answer: a
Explanation: The cupola furnace can be turned and tilted to a certain degree through which the basic operations can be performed. The materials which form the lining are eroded once the metal is removed from the cupola. Hence, it is necessary to replace them and due to freedom of movement it is possible to do so.
This set of Foundry Multiple Choice Questions & Answers focuses on “Principles of Foundry”.
1. _____________ is a process of preparing a casting.
a) Founding
b) Forging
c) Melting
d) Pouring
Answer: a
Explanation: Founding is a process of producing metal/alloy component parts of the desired shapes by pouring the molten metal/alloy into a prepared mould and then allowing it to solidify. The solidified piece is called as casting.
2. Which of the following is prepared using pattern is foundry?
a) Mould
b) Sand
c) Core
d) Mould, Sand and Core
Answer: d
Explanation: The process of foundry always results in the formation of casting. It depends on the pattern of the casting on what type of mould and core is to be prepared. The suitability of the sand also depends on the type of pattern is used to produce the casting.
3. Fettling is the last step of the foundry.
a) True
b) False
Answer: a
Explanation: The fettling involves cleaning of the casting and making it of the dimension as needed for the customer. The fettling can also involve machining. Once fettling is over the casting is ready for dispatch. Hence, it is the last step of the foundry process.
4. Which of the following metal castings are used to make casting in the foundry?
a) Brass
b) Aluminum
c) Iron
d) Brass, Aluminum and Iron
Answer: d
Explanation: The commonly used materials used to make casting in foundries are aluminum and cast iron. However, special arrangements are to be made to make castings of Brass, steel and magnesium as they differ in their melting temperature. Variety of castings can be made in the foundry.
5. To form castings, always virgin metal is used in foundries.
a) True
b) False
Answer: b
Explanation: The virgin metal is nothing but the pure metal that is to be used. It is a non-economical way as there is a large amount of scrap available to form these castings. The principle of foundry also involves reusing of scrap and reducing the wastage as much as possible.
6. _________ tuyeres increase the melting efficiency.
a) Single
b) Double
c) Auxiliary
d) Blast
Answer: c
Explanation: The tuyeres are responsible for the supply of air for combustion in the cupola. The tuyeres are always fitted in one or more number of rows. Auxiliary tuyeres being more efficient are fitted in the cupola to supply more air and increase melting efficiency.
7. The foundry uses ___________ process to relieve stresses produced in castings.
a) Reforming
b) Heat treatment
c) Water treatment
d) Cooling
Answer: b
Explanation: The method used to prepare a casting imparts high stress to the walls of the casting due to the extensive process involved. Heat treatment is the most economical method used by the foundry to relieve the stress and ready the casting.
8. The product of the foundry process is ____________
a) Binders
b) Pattern
c) Casting
d) Metal
Answer: c
Explanation: The foundry process has many operations such as pattern making, sand preparation etc. After all the process, the product is got from separating it from the sand stuck to it. The product is called the casting while the rest all is open which is used to make a casting.
9. Casting is the most versatile process in manufacturing.
a) True
b) False
Answer: a
Explanation: The casting or the foundry process provides the greatest freedom of design in terms of shape, size and product quantity. Hence, it is the most versatile process in manufacturing till date.
10. Foundry processes cannot be mechanized.
a) True
b) False
Answer: b
Explanation: The foundry process involves various machines such as sand slinger, jolt squeezer machine which automate the molding process and the conveyor belts used are used to transport the mold boxes. As these process are mechanized several other processes can be mechanized as well.
This set of Foundry Multiple Choice Questions & Answers focuses on “Raw Materials for Foundry”.
1. Ore is _________ to make it suitable for foundry processes.
a) Smelted
b) Melted
c) Extracted
d) Refined
Answer: a
Explanation: Smelting is form of extractive metallurgical process which is responsible for the extraction of various metals from the ores that are available in the earth’s crust. Hence, the ores are smelted to make them feasible to use in the foundry processes.
2. The metals that are used in foundries are obtained in which of the following sources?
a) Oxides
b) Sulphides
c) Carbonates
d) Aldehydes
Answer: d
Explanation: The aldehyde is an organic compound which contains a functional group which has the structure of –CHO group. They are formed by oxidation of alcohol which is not available in the crust. As it is in liquid form it is chemically prepared and is not available in the crust.
3. Anthracite coal is used to melt the metals in foundry.
a) True
b) False
Answer: a
Explanation: Anthracite coal is the best type of coal among the other type of coals. The anthracite coal has the least amount of impurities and it releases less amount of pollution and more energy and hence it is used in foundries.
4. The source of energy that keeps the furnace the cleanest is __________
a) Electricity
b) Water
c) Air
d) Sunlight
Answer: a
Explanation: In a foundry, electricity is the easiest and the most expensive source of energy available. When the furnaces are electrically powered, there is no amount of smoke found and the particulate matter does not settle down. Hence, it keeps the furnaces clean.
5. Charcoal is the prime material used in copper-alloy foundry.
a) True
b) False
Answer: a
Explanation: In copper-alloy foundry practice, charcoal is used to prevent the molten metal from being oxidized, and some commercially available fluxes may be employed to cleanse the metal that is to separate it from dross. Hence it is a prime material in the copper-alloy foundry.
6. The flux used in the foundries to make castings of magnesium alloys are ________
a) Potassium Chloride
b) Barium Chloride
c) Magnesium Oxide
d) Potassium Chloride, Barium Chloride and Magnesium Oxide
Answer: d
Explanation: The fluxes are used for melting magnesium alloys prevent the burning of magnesium alloys. The fluxes listed above have excellent properties as fluxes in foundries. Nitrogen is used to bubble slowly through the molten magnesium for removing hydrogen.
7. The melting point of the flux is _________
a) Low
b) High
c) Room Temperature
d) Critical
Answer: a
Explanation: The flux, when heated up, melts and combines with the ash, viscous slag, sand, metallic oxides etc., and make a flowing slag. To form the slag, it is important for the flux to be composed of the low melting point.
8. _____________ protects molten metal from atmosphere in the foundry.
a) Pattern
b) Mould
c) Slag
d) Refractories
Answer: c
Explanation: The slag being the lighter part comes on to the surface of the molten metal from where it can be easily skimmed, tapped or removed before pouring the metal into the mould. Hence, the slag does not allow the metal to be in contact with the atmosphere.
9. In the foundry, the electric furnaces cannot operate for high temperatures.
a) True
b) False
Answer: b
Explanation: The electric furnaces usually operate up to high temperatures of 1700 o C. As the electric induction and electric resistance furnaces are used to melt almost all types of metals, it is seen that electric furnaces operate at a wide range of temperatures.
10. Limestone removes sulphur from cast iron.
a) True
b) False
Answer: a
Explanation: Limestone is chemically known as sodium carbonate. It is used in cupola while melting cast iron. It gives rise to a slag which removes sulphur from cast iron in foundry processes.
This set of Foundry Multiple Choice Questions & Answers focuses on “Advantages and Applications of Foundry”.
1. Scope of automation in foundry process is _____________
a) Low
b) High
c) Minimum
d) Maximum
Answer: a
Explanation: The foundry processes are extensively laborious while compared to other manufacturing processes. The productivity when compared to efforts is low. The processes can be mechanized but not automated.
2. Which of the following is an advantage of the Green sand molding process used in a foundry?
a) Appropriate for long production run
b) Very low cost process
c) Sand is reusable
d) All of the mentioned
Answer: d
Explanation: The green sand has an adequate amount of water which is lost during the process but it can be restored by adding the same and it is fit for reusing. This enables it to be usable for longer production at less cost. Hence, the green sand molding is employed in most foundries.
3. The castings in formed in foundry produced are accurate in dimensions.
a) True
b) False
Answer: b
Explanation: The dimensions of the casting depend on the method of preparation employed. Investment mould casting gives higher dimensional accuracy whereas the sand casting gives low dimensional accuracy.
4. The _______ energy consumption is a drawback of the foundry.
a) High
b) Optimum
c) Intensive
d) Low
Answer: a
Explanation: In a foundry, the sources of energy used are large in number. The major drawback of the foundry is that the energy consumption in terms of material, refractories and metal is very high.
5. Majority parts in transportation vehicles are made by the foundry processes.
a) True
b) False
Answer: a
Explanation: Cast metal parts account for more than 90% of an automobile engine and for more than 50% of the total weight of the tractor. Thus, most of the parts are made of cast iron are manufactured in foundries.
6. ______________ defects in castings cannot be identified easily.
a) Internal
b) External
c) Chemical
d) Metallic
Answer: a
Explanation: The casting is usually made in bulk in foundries and it is not visible to the naked eyes. The castings have to be sent for X-ray testing and such kind of test to find out the internal defects. Identifying internal defects is a tough task in foundries.
7. Castings are usually designed for ________ distribution of loads.
a) Equal
b) Unequal
c) Maximum
d) Minimum
Answer: a
Explanation: The castings are designed for the equal distribution of loads on all the members of the product and for minimum stress concentration in order to achieve more strength and more service life of the casting.
8. The _______ directional properties are imparted to the castings made in foundries.
a) Single
b) Double
c) Spherical
d) Multiple
Answer: a
Explanation: When the pouring takes place in the foundry, the uniform melting of the metal is ensured so that the casting prepared has adequate strength. This imparts a uniform and a single directionality to the castings that are produced and provides better vibration damping capacity to the cast parts.
9. In the foundry, the metal joining process is employed.
a) True
b) False
Answer: b
Explanation: The foundry produces the castings that are in a single piece. Even if the pattern of the first and second half is different, it produces the casting in a single piece. Hence, the metal joining process is eliminated in the foundry.
10. Foundry process is used to make intricate parts.
a) True
b) False
Answer: a
Explanation: The foundry process is suitable for both small and large components. It gives a high rate of production, small dimensional tolerances and good surface finish. Due to these properties, it can be used to produce intricate parts.
This set of Foundry Multiple Choice Questions & Answers focuses on “Cores and Core Prints”.
1. ___________ forms a seat in mold on which the sand core rests during pouring.
a) Pattern
b) Sand
c) Core
d) Core Print
Answer: d
Explanation: The core print is just like an added projection on the pattern and it must be of the adequate size and shape so that it can support the weight of the core during the casting operation.
2. Which of the following is a property of core material used in a foundry?
a) Appropriate for long production
b) Low Weight
c) Reusable
d) Core Print
Answer: b
Explanation: The core materials are always composites skins which create a sandwich structure. The main property looked for its functionality is the high stiffness and low weight.
3. The use of cores is always dependent on the type of sand used.
a) True
b) False
Answer: a
Explanation: The design of the casting depends upon the area where it is supposed to be used. Hence, the sand type is a major function of the foundry. The core is dependent on the sand as it comes in contact with it.
4. The _______ is responsible for cavities in castings in the foundry.
a) Patterns
b) Sand
c) Cores
d) Riser
Answer: c
Explanation: In a foundry, a core is usually placed in the mould box as a separate entity or the integrated part of the pattern to form a castings that has intricate parts and when it requires to produce internal cavities and reentrant angles.
5. A core is a disposable item but it can be reused from time to time.
a) True
b) False
Answer: b
Explanation: A core is a device which is normally made up of sand. The technology of metallic cores is emerging in manufacturing technology. The core when used once usually comes out in the burnt form and hence even though it is disposable, it cannot be reused.
6. The number of cores to be used to form castings is _____________
a) One
b) Ten
c) Depends on the sand
d) Depends on the design
Answer: d
Explanation: The number of cores used in the formation of the casting depends hugely on the design. The range of the cores used cannot be specified. The valves require two or three cores depending on the design where as the GM V-8 engines require 5 dry sand cores.
7. ___________ cores cannot make long narrow features.
a) Green Sand
b) Dry-Sand
c) Metallic
d) Lost
Answer: a
Explanation: The Green sand cores make a casting of the long narrow features difficult or impossible. Even for long features that can be cast, it will still leave much material to be machines.
8. Which of the following process is not used to remove the cores from the finished casting?
a) Blowing
b) Melting
c) Washing
d) Chemical Dipping
Answer: b
Explanation: When the air is blown, the particles of the burnt core are removed. Similarly, the washing and chemical methods are used when the adhesive properties of the core particles are high. The core melts when the hot metal is poured over it. Hence, this process cannot be used for cleaning.
9. The dimensional accuracy of the cores is low.
a) True
b) False
Answer: a
Explanation: The foundry procedures are tedious and difficult. The cores are required to produce the intricacies and cavities. The cores are produced by using the sand and other such materials and hence the dimensional accuracy of the cores in such cases becomes low.
10. Binders are added to increase the strength of the core.
a) True
b) False
Answer: a
Explanation: The foundry process requires binders for almost every application. The making of the cores requires binders for the making of cores. The binder quantity increases the adhesive properties of the core and it can be used to increase the dimensional accuracy of the cavity.
This set of Foundry Multiple Choice Questions & Answers focuses on “Properties of Moulding Sand”.
1. In order the get a smooth casting, the size of the sand particles should be _________
a) Coarse
b) Fine
c) Moderate
d) Large
Answer: b
Explanation: The fine grains are the sand particles which has a lower grain size. This lower grain sized particles always form a smooth surface over which the curves and edges can be dimensionally mapped. The fine particles allow less distortion of the metal and the surface obtained by them on the casting is smooth.
2. Which of the following is not used for the formation of the molding sand?
a) Silica Sand
b) Binders
c) Additives
d) Coal
Answer: d
Explanation: The coal is a material which is not used in the formation of the molding sand as the particle size of the coal is high and there are chances that it will react with the possible gases that are produced during the pouring of the metal and result in casting defects.
3. The size of the sand particles in the molding sand is the biggest.
a) True
b) False
Answer: a
Explanation: The molding sand is made up of several particles. The properties such as porosity, texture are all considered while making it fit for the use of the foundry. Out of all the materials used, the size of the sand particles is the highest.
4. The _______ is responsible for the impact strength in the molding sand.
a) Aggregates
b) Refractoriness
c) Impurities
d) Permeability
Answer: a
Explanation: In a foundry, the molding sand forms an important part of the cope and drag. It should have high impact strength, stability and permeability and this is imparted by silica sand in the form of granular quarts which has enough refractoriness to cast all of these strengths to the molding sand.
5. Molding sand can withstand chemical reactions on it and prove it to be beneficial for the casting formation.
a) True
b) False
Answer: b
Explanation: Molding sand is added with chemicals to enhance properties such as permeability, Compressive strength etc., however, the chemical reactions happening is not viable for the formation of the casting as it might cause explosion or severe fatal effects in the casting.
6. The _______________ property ensures the removal of excess sand in the mould box.
a) Adhesiveness
b) Cohesiveness
c) Green strength
d) Compressive strength
Answer: a
Explanation: The adhesiveness is a property of molding sand to get the stick or adhere to foreign material such as sticking of molding sand with an inner wall of the molding box. Hence, as the sand sticks to the box and the excess sand is removed.
7. Binding property of the sand increases because of the ____________ property.
a) Cohesiveness
b) Collapsibility
c) Flow ability
d) Permeability
Answer: a
Explanation: The cohesiveness is a property of molding sand by virtue which the sand grain particles interact and attract each other within the molding sand. Hence, the binding capability of the molding sand gets enhances to increase the green, dry and hot strength property of molding and core sand.
8. Which of the following is the most important property of the molding sand in cores?
a) Dry Strength
b) Green strength
c) Collapsibility
d) Cohesiveness
Answer: c
Explanation: After the molten metal in the mould gets solidified, the sand mould must be collapsible so that free contraction of the metal occurs and this would naturally avoid the tearing or cracking of the contracting metal. In absence of collapsibility property, the contraction of the metal is hindered by the mold and thus results in tears and cracks in the casting. This property is highly required in cores.
9. The adhesiveness and cohesiveness are the same properties of the molding sand.
a) True
b) False
Answer: b
Explanation: The adhesive property refers to the sticking of the sand particles to each other so that they can take up the desired shape. But, cohesiveness refers to the property where the particles react and interact with each other and attract to increase the strength. Hence, the terms are different.
10. Flow ability increases with increase in the green strength.
a) True
b) False
Answer: a
Explanation: Flowability or plasticity is the ability of the sand to get compacted and behave like a fluid. It will flow uniformly to all portions of a pattern when rammed and distribute the ramming pressure evenly all around in all directions. Generally, sand particles resist moving around corners or projections. In general, flowability increases with a decrease in green strength and vice versa.
This set of Foundry Multiple Choice Questions & Answers focuses on “Sand Control Tests”.
1. _____________ is used to remove moisture content in the molding sand.
a) Moisture teller
b) Green Strength
c) Cone Jolt
d) Clay test
Answer: a
Explanation: In the moisture teller, the sand is dried by suspending the sample on a fire metallic screen and allowing hot air to flow through the sample. This method of drying completes the removal of moisture in a matter of minutes.
2. The molding sand is prepared by ______________method.
a) Sand Mueller
b) Manual work
c) Sand sieve
d) Rotator
Answer: a
Explanation: The sand Mueller is a device that mixes the sand in appropriate amount. It is subjected to regular rotation with the help of the motor and current. The additional ingredients are added externally. The sand is then supplied by the conveyor belts.
3. High moisture content decreases the permeability of the molding sand and it can be detected by moisture content test.
a) True
b) False
Answer: a
Explanation: The molding sand has moisture as a dominant property. It is defined as the amount of water present in the molding sand. As the low moisture content in the molding sand does not develop strength properties, the high moisture content decreases permeability.
4. The samples of the moisture test are prepared in _______ heater bulb.
a) Infrared
b) X-ray
c) Radio
d) Ultraviolet
Answer: a
Explanation: In a foundry testing lab, the samples used for moisture test are 20 to 50 grams of the prepared sand place in the pan and heated by an infrared heater bulb for 2 to 3 minutes. The wavelength of the infrared rays is high enough to generate heat and evaporate the moisture.
5. The top sieve of the sand sieve analysis is the finest.
a) True
b) False
Answer: b
Explanation: In the sand sieve analysis, the sieves are placed one upon the other and shaked so that the finer grains are obtained. They are arranged in descending order from top to bottom and the top most sieves are the coarsest as it has the biggest mesh.
6. The Sand Sieve Analysis is used for _____________
a) Grain Fitness test
b) Grain Size test
c) Green strength test
d) Compressive strength test
Answer: a
Explanation: The grain size, distribution, grain fitness are determined with the help of the fitness testing of moulding sands. The apparatus consists of a number of standard sieves mounted one above the other, on a power-driven shaker.
7. _________ measures air pressure in air permeability test.
a) Barometer
b) Manometer
c) Bell jar
d) Tube
Answer: b
Explanation: The quantity of air that will pass through a standard specimen of the sand at a particular pressure condition is called the permeability of the sand. This is a major sand control test. Hence, a manometer is used.
8. Which of the following tests are done for molding sand strength?
a) Compression
b) Tension
c) Shear
d) Compression, Tension, Shear
Answer: d
Explanation: Measurements of strength of molding sands carried out on the universal sand strength testing machine. The strength measured such as compression, shear and tension. The sands that could be tested are green sand, dry sand or core sand. The compression and shear test involve the standard cylindrical specimen that was used for the permeability test.
9. The green compression tests of the strength tests required to be very high.
a) True
b) False
Answer: a
Explanation: Green compression strength or simply green strength generally refers to the stress required to rupture the sand specimen under compressive loading. The sand specimen taken out of the specimen tube and immediately put on the strength testing machine and the force required to cause the compression failure is determined. The green strength of sands is generally in the range of 30 to 160 KPa.
10. The mould hardness is tested in the same way as the Brinells hardness test.
a) True
b) False
Answer: a
Explanation: A spring loaded steel ball is indented into a standard specimen prepared. The depth of indentation can be directly measured on the scale which shows units. When no penetration occurs, then the hardness of 100 and when it sinks completely, the reading is zero indicating a very soft mould. The same procedure is followed in checking the Brinells hardness number.
This set of Foundry Multiple Choice Questions & Answers focuses on “Pattern Materials”.
1. _____________ is used as a pattern material for the easy handling of the equipment.
a) Wood
b) Charcoal
c) Steel
d) Lead
Answer: a
Explanation: In all the pattern materials, wood is a material which is widely used. The properties of the wood being easy availability and low weight make it sustainable for the longer run. Hence, it is used as a pattern material for easy handling of the equipment.
2. Which of the following is the most pattern materials are corrosion prone?
a) Grey Cast Iron
b) Steel
c) Brass
d) Lead
Answer: a
Explanation: The Grey cast iron is a ferrous component hence it is corrosion prone. Even though the steel is an alloy of Iron, it is heterogeneous component and is less prone to corrosion than Grey cast Iron.
3. Wooden patterns have a high maintenance cost.
a) True
b) False
Answer: a
Explanation: The wooden patterns can be shaped easily and are relatively cheap. But the main disadvantage of wood is its absorption of moisture as a result of which distortions and dimensional changes occur. A good construction may be able to reduce the war page to some extent. Hence, proper seasoning and upkeep of wood is a pre-requisite for large scale use of wood as a pattern material.
4. Which of the following types of wood are used to make patterns?
a) Pine
b) Walnut
c) Teak
d) Deodhar
Answer: b
Explanation: All of the above mentioned types of wood are used to make pattern due to the wide availability and the property of the wood to sustain for a long duration and yields dimensional accuracy.
5. Plywood boards are used for making patterns requiring high impact strength.
a) True
b) False
Answer: a
Explanation: The plywood boards of veneer type as well as the particle boards are also used for making patterns. Because of their availability in various thickness, their higher strengths and no need for seasoning are the reasons for their usage. However, they can be used only in patterns which are the flat type and no three-dimensional contours.
6. The ____________ is used for making additional patterns with minimal double shrinkages.
a) Aluminium
b) White Metal
c) Steel
d) Grey Cast Iron
Answer: b
Explanation: The white metal is light, can be easily worked and is corrosion resistant. Since white metal has very small shrinkage, the white metal pattern can be made use of for making additional patterns without worrying about the double shrinkage allowances.
7. _________ patterns are useful for large castings in the foundry.
a) Steel
b) Lead alloys
c) Aluminium alloys
d) Wood
Answer: d
Explanation: The quantity of wood required for the large castings’ pattern is high. The manufacturing of large casting requires high dimensional accuracy as several parts of the casting cannot be machined. Hence wood is the only practical pattern material.
8. Which of the following plastic is used for making patterns?
a) Epoxy resins
b) Thermoplastics
c) Thermosetting plastics
d) Polyvinyl chloride
Answer: a
Explanation: The making of a plastic pattern can be done by sand clay moulds or moulds made of plaster of Paris. Hence, the cold setting epoxy resins with suitable fillers are used. With a proper combination, it is possible to obtain a no shrink plastic material and as such double shrinkage allowances may not be required.
9. The plastic patterns give the highest dimensional accuracy.
a) True
b) False
Answer: a
Explanation: Plastics are used as pattern materials because of their low weight, easier formability, smooth surfaces and durability. They do not absorb moisture and are therefore, dimensionally stable and can be cleaned easily.
10. The metal pattern is more useful over wood patterns.
a) True
b) False
Answer: a
Explanation: Molding sand is made up of highly abrasive particles for the large scale production and metal pattern provide higher resistance to abrasion over the wood patterns. Hence, where ever possible, metal patterns are preferred over the wood patterns.
This set of Foundry Problems focuses on “Sections in the Foundry”.
1. _____________ is the most often used method for making of the complex shapes that are uneconomical to manufacture by other methods.
a) Foundry
b) Machine Shop
c) Assembly Line
d) CNC
Answer: a
Explanation: In all the above mentioned ways, the basic function is the same that is the preparation of final products. But, the foundry is responsible for making up of castings which is often complex in shape and it cannot be made by manual methods. Usually, ferrous and non-ferrous alloys are employed for making castings.
2. Which of the following is the furnace used for melting in foundries?
a) Cupola
b) Assembly Line
c) Pit Furnace
d) Electric Induction
Answer: a
Explanation: Out of all the furnaces, Cupola is largely used by the melting department in the foundry. Due to the varying sizes of the cupola the amount of metal melted is usually high and the materials required to charge the cupola are also widely available. Hence, the cupola is used in melting.
3. Castings of only ferrous materials can be made in foundries.
a) True
b) False
Answer: b
Explanation: The most common metals processed are aluminium and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed.
4. Which of the following is not included in scrap used for melting?
a) Risers
b) Billets
c) Defective castings
d) Gates
Answer: b
Explanation: All of the above mentioned types of materials are scraps from the earlier used materials except for billets. A billet is a form of cylindrical shaped raw materials which is melted and solidified to get to that shape after purification. Billets are externally prepared for ease of transportation and are not a scrap.
5. Shaking out is the easiest way to remove the sand from the castings after is it solidified.
a) True
b) False
Answer: a
Explanation: Shakeout frees the casting from the sand, which is attached to the metal runners and gates — the channels through which the molten metal traveled to reach the component itself. It is either done mechanically or manually.
6. The ____________ process is employed to remove gases.
a) melting
b) pouring
c) scrapping
d) refining
Answer: d
Explanation: The Refining is done to remove deleterious gases and elements from the molten metal to avoid casting defects. The material is added during the melting process to bring the final chemistry within a specific range specified by industry and/or internal standards.
7. The pouring is accomplished by ______________ force.
a) electromagnetic
b) magnetic
c) gravitation
d) friction
Answer: a
Explanation: In a foundry, molten metal is poured into molds. Pouring can be accomplished with gravity, or it may be assisted with a vacuum or pressurized gas. Many modern foundries use robots or automatic pouring machines to pour molten metal. Traditionally, molds were poured by hand using ladles.
8. Which of the following plastic is not obtained from degating?
a) Gates
b) Risers
c) Runners
d) Cores
Answer: d
Explanation: The cores are made up of sand and are placed in the mould box to create cavities in the castings. Once the metal is poured and solidified, the cores are obtained in an amorphous form and cannot be withdrawn.
9. The heat treatment alters the properties of the materials and enhances them according to their functionality and material.
a) True
b) False
Answer: a
Explanation: Heat treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical aspects in the foundry and machine shop. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, and quenching.
10. The machining is the integral and last step in the foundry industry.
a) True
b) False
Answer: a
Explanation: The final and the integral step in the process of casting usually involves grinding, sanding, or machining the component in order to get the desired dimensional accuracies, physical shape, and surface finish. All of this is taken care by the machining shop.
This set of Foundry online test focuses on “Moulding Sand Binders and Additives”.
1. _____________ is the mixture offering a very high stability to the mould.
a) Bentonite
b) Dextrin
c) Molasses
d) Lumber
Answer: a
Explanation: High quality bentonite bonded molding sands are able to offer the optimum solution for mold stability, providing not only the requisite mechanical properties but the necessary flexibility for the production of castings that comply with the ever stringent demands for quality and productivity.
2. Which of the following is the most basic binder used in the molding sand?
a) Clay
b) Zircon
c) Alumina
d) Manganese oxide
Answer: a
Explanation: Even though the major portion of the molding sand in silica , clay and water form the binder component of this sand. It is used to provide these sand grains adhesive property so that the grains stick to the pattern to form a casting of appropriate and required shape.
3. Oxides of alumina are always treated as impurities in the molding sand.
a) True
b) False
Answer: b
Explanation: The oxides of alumina, sodium and magnesium have excellent binding properties. They are added to the molding sand to enhance its mold ability and dimensional properties. However, their constituency should be limited to 2% or less as its excess quantity can cause defects in the castings and effect the fusion point of silica sand.
4. ____________ sand is highly used for investment casting process.
a) Silica Sand
b) Zircon
c) Loam sand
d) Chromite sand
Answer: b
Explanation: The Zircon sand has high thermal conductivity, high chilling power and high density. It requires a very small amount of binder. It is used to manufacture precision steel castings requiring better surface finish which is the main objective of the investment casting process.
5. Chromite sand requires the least amount of binders.
a) True
b) False
Answer: a
Explanation: Chromite sand is crushed from the chrome ore. As the fusion point of this sand is high as 1800 C, it requires a small amount of binder . It is also used to manufacture heavy steel castings requiring a better surface finish.
6. The ____________ sand is the most versatile sand.
a) Loam sand
b) Chromite sand
c) Kaolinite
d) Olivine sand
Answer: d
Explanation: The olivine sand contains all the minerals such as Fosterite (Mg 2 SiO 4 ) and Fayalite (Fe 2 SiO 4 ) which is suitable for almost all the type of casting manufacturing processes. The same mixtures can be used for a range of steels but it is very expensive.
7. The ________ is used to activate the clay binders to perform its functions.
a) Water
b) Helium gas
c) Nitrogen gas
d) Alkali metals
Answer: a
Explanation: In a foundry, clay is used in the form of bentonite which requires water to activate itself. Bentonite can absorb more water which increases its bonding power. The clay also activates the other basic constituents like mixtures of lime and alkalis to reduce refractoriness.
8. Which of the following binder immediately increases the binding properties?
a) Cereal binder
b) Clay
c) Pitch
d) Silica
Answer: a
Explanation: The Cereal binder when added to the molding sand increases the binding properties by 2% as soon as it is added. It has excellent mixing properties and the wide availability increases its probability of being used.
9. The sodium bentonite binder imparts swelling properties to the molding sand.
a) True
b) False
Answer: a
Explanation: Sodium Bentonite provides better swelling properties- volume increases some 10 to 20 times, high dry strength which lowers the risk of erosion, better tolerance of variations in water content, low green strength and high resistance to burnout, which reduces clay consumption.
10. Sodium bentonite and Calcium bentonite has the same binding properties.
a) True
b) False
Answer: b
Explanation: Sodium and Calcium bentonite has contras properties. Sodium Bentonite provides better swelling properties volume increases some 10 to 20 times, high dry strength which lowers the risk of erosion whereas the Calcium Bentonite has the low dry strength but higher green strength.
This set of Foundry Question Bank focuses on “Moulding Sand Preparation and Conditioning”.
1. In the following equation, P stands for _________
foundry-questions-bank-q1
a) Permeability number
b) Pressure
c) Partial Pressure
d) Partial Fraction
Answer: a
Explanation: The equation given above is the standard equation for the measurement of the permeability number. After preparing the test sample of sand, 2000 cm3 of air is passed through the sample and the time taken by it to completely pass through the specimen is noted. Then its permeability is calculated using the above equation.
2. The rate of flow of air passing through a standard specimen under a standard pressure is termed as _____________
a) Green Strength
b) Dry Strength
c) Mould Hardness Number
d) Permeability number
Answer: d
Explanation: The standard permeability number test is to measure time taken by a 2000 cm3 of air at a pressure typically of 980 Pa to pass through a standard sand specimen confined in a specimen tube. The standard specimen size is 50.8mm in diameter and length of 50.8 mm.
3. Measurement of strength of molding sands can be carried out on a Universal testing machine.
a) True
b) False
Answer: a
Explanation: The measurement of the strength of molding sands can be carried out on the universal sand strength can be measured in compression, shear and tension. The sands that could be tested are green sand dry sand or core sand. The compression and shear test involves the standard cylindrical specimen that was used for the permeability test.
4. Permeability is greatly dependent upon ________________
a) Ramming of sand
b) Sand Particle size
c) Sand grade
d) Moisture content
Answer: a
Explanation: The permeability of sand is dependent to a great extent, on the degree of ramming, it is necessary that the specimen be prepared under standard conditions. To get reproducible ramming conditions, a laboratory sand rammer is used along with a specimen.
5. Green shear strength is more than the Green compression strength.
a) True
b) False
Answer: b
Explanation: The Green compression strength that was used is generally in the range of 30 to 160 kPa and the Green shear strength can vary from 10 to 50 kPa according to the standards of the sands.
6. The strength of the sand ____________ on drying.
a) Remains same
b) Increases
c) Decreases
d) Depends on the sand
Answer: b
Explanation: The tests are carried out with the standard specimen dried between 105 and 110 C for 2 Hours. Since the strength increases greatly with drying, it may be necessary to apply larger stresses than the other similar tests.
7. The mould hardness measuring test is similar to _________
a) Brinells Hardness test
b) Vikers hardness test
c) Rockwell Hardness test
d) Sand Grain analysis
Answer: a
Explanation: In a foundry, the mould hardness is measured by a method similar to Brinell hardness test. A spring loaded steel ball with a mass of 0.9 kg is indented into the standard sand specimen prepared. The depth of the indentation can be directly measured on the scale.
8. Which of the following binder immediately increases the binding properties?
a) Cereal binder
b) Clay
c) Pitch
d) Silica
Answer: a
Explanation: The Cereal binder when added to the molding sand increases the binding properties by 2% as soon as it is added. It has excellent mixing properties and the wide availability increases its probability of being used.
9. The iron oxide reduced the hot strength.
a) True
b) False
Answer: b
Explanation: Iron oxide is used approximately in the amount of 3% in the moulding sand. It is used to improve the surface finish, decrease metal penetration and reduces the burn-on. Hence, it decreases the green strength and permeability while improving the hot strength.
10. Molasses enhances the bench life of the sand and is the best sand conditioner.
a) True
b) False
Answer: a
Explanation: The molasses is the organic product got from the sugar industry. This organic binding material is used with the mould and core sand. They increase the resistance to deformation and improve bench life.
This set of Foundry Multiple Choice Questions & Answers focuses on “Types of Sand Moulds”.
1. In the molding sands, which of the following are the major properties?
a) Permeability
b) Sand Grains
c) Size of the grains
d) Permeability, sand grains and size of the grains
Answer: d
Explanation: The shape and size of the sand grain would greatly affect the various molding sand properties. The sand grain size and the sand grain could be coarse or fine and the grain shape should be round or angular. The sand permeability should depend on the type of casting to be manufactures. All these properties make a sand quality optimum.
2. The rate at which the casting is removed from the green sand mould is __________
a) Immediately
b) Min 2-3 hours later
c) More than 6 hours
d) Around 2 days
Answer: a
Explanation: In a green sand mould, metal is poured immediately and the casting taken out. These are most commonly used and are adapted for rapid production, where the molding flasks are released quickly.
3. Green sand mould acquires the highest floor space.
a) True
b) False
Answer: b
Explanation: The green sand mould is used for the rapid production of the castings. It can be used to produce a wide range of castings. As the mould is produced, the casting is prepared. Hence, it requires less floor space as no storage is involved.
4. Hot tearing of the casting is least observed in _______________
a) Green sand moulds
b) Dry sand moulds
c) Skin dried sand moulds
d) Size of the grain
Answer: a
Explanation: The hot tearing of the casting refers to the one of the types of casting defect that weakens the strength of the casting defects. As the moisture is present in the green sand mould, the hot tearing is considerably reduced in the green sand mould.
5. All the sand moulds should have a great venting capacity.
a) True
b) False
Answer: a
Explanation: The venting is done in the sand moulds so that the gases are let out after the metal is poured in it. If these gases are not let out, they tend to form casting defects on the surface of the castings. Hence all the sand moulds should have great venting capacity.
6. The permeability _________ with the grain size.
a) Remains same
b) Increases
c) Decreases
d) Depends on the sand
Answer: b
Explanation: The grain size increases with the coarse grains. The coarse grains would have more void space between the grains which increases with permeability. Similarly, the finer grains would have lower permeability.
7. Uncontrolled permeability in the green sand mould leads to ___________
a) Blow Holes
b) Chills
c) Shrinkage
d) Tearing
Answer: a
Explanation: The rate of flow of air passing through a standard specimen under a standard pressure is termed as a permeability number. The permeability of these holes should be properly controlled, otherwise blow holes and gas inclusions are likely to form.
8. The strength of the dry sand mould depends on ________
a) Sand Quality
b) Sand grain
c) Binders
d) Additives
Answer: c
Explanation: The dry sand mould is prepared using the heating method. Dry sand moulds are the green sand moulds which are completely dried by keeping in an oven in 150 to 350 C for 8 to 48 hours. Due to the great interference of heat, the strength is dependent on the binders in the molding sand.
9. Dry sand moulds have high strength than the green sand moulds to form large castings.
a) True
b) False
Answer: a
Explanation: Dry sand moulds gave higher strengths than the green sand mould and are preferred because they are less likely to be damaged during handling. Hence they are generally used for medium and large castings.
10. Skin dried mould is preferable for large moulds over the dray sand moulds.
a) True
b) False
Answer: a
Explanation: Though the dry sand mould is preferable for large moulds because of the expense involved, the compromise is achieved by drying only the skin of the mould cavity with which the molten metal comes into contact, instead if the full mould.
This set of Foundry Multiple Choice Questions & Answers focuses on “Types of Patterns”.
1. ____________ pattern could fit entirely in the cope or in the drag.
a) Single piece
b) Match plate
c) Two piece
d) Gated Pattern
Answer: a
Explanation: The single piece pattern is made up of a single piece as its name suggests. One of the faces is expected to be which is used as a parting plane. Hence, it can be said that it could fit entirely in the drag.
2. The ________ pattern could have the entire assembly of runner and gates integrated in it.
a) Single piece
b) Match plate
c) Two piece
d) Gated Pattern
Answer: d
Explanation: The gated pattern is an improvement in the single piece pattern where the gating and the runner system are integral with the pattern. This would eliminate the hand cutting of the runners and gates and helps in improving the productivity of the molder.
3. Two piece patterns are used for manufacturing of the intricate castings.
a) True
b) False
Answer: a
Explanation: The two piece patterns are used for large production of castings. The patterns are used for the castings where it is not possible to form the casting in one piece and where the removing of the casting without contour is difficult.
4. Dowel pins, Jigs and fixtures are all used to join which of the following patterns.
a) Single piece
b) Match plate
c) Two piece
d) Gated Pattern
Answer: c
Explanation: The two piece patterns are made using one single pattern cut in two halves. Once is placed in the cope and other in the drag. To facilitate the proper alignment of the of the halves in the cope and the drag, they are joined with the jigs, fixtures and dowel pins.
5. Cope and drag pattern uses separate wooden plates and alignment pins.
a) True
b) False
Answer: a
Explanation: The cope and drag pattern are similar to a split pattern. In addition to splitting the pattern, the cope and drag halves of the pattern along with the gating and risering systems are attached separately to the metal or wooden plates along with the alignment pins. Hence, they are called to cope and drag patterns.
6. Manual or Machine cutting of runners and gates is eliminated in ______________
a) Split Pattern
b) Single piece pattern
c) Gated Pattern
d) Match Plate Pattern
Answer: c
Explanation: Gated Pattern is a pattern where the gating and runner system is integral with a pattern. A Gated Pattern consists if the molding and control patterns, jigs, the drying plates and the stripping place all embedded in it. Once the pattern is removed it is removed automatically.
7. Structurally weak castings are made using _____________
a) Loose piece pattern
b) Sweep Pattern
c) Skeleton Pattern
d) Follow board pattern
Answer: d
Explanation: The follow board pattern is adopted for those castings where there are some portions which are structurally weak and if not supported properly are likely to break under the force of ramming.
8. ________ is used to make the large castings of axi-symmetrical shapes.
a) Loose piece pattern
b) Skeleton pattern
c) Sweep pattern
d) Match plate pattern
Answer: c
Explanation: The sweep pattern to sweep the complete casting by means of a pattern. These are used for generating large shapes which are axi-symmetrical or prismatic in m=nature such as bell shaped or cylindrical. This greatly reduces the cost of 3 D pattern.
9. During the preparation of cope using the follow board pattern, the follow board is not necessary.
a) True
b) False
Answer: a
Explanation: During the preparation of the cope, no follow board is necessary because the sand which is compacted in the drag will support the fragile pattern.
10. Match plate pattern is made using wood.
a) True
b) False
Answer: b
Explanation: The complete pattern with the match plate is entirely made up of metal, usually aluminium for its light weight and machinability. But when the dimensions are critical, the match plate may be made up of steel with necessary case hardening of the critical wear points.
