This set of Foundry Multiple Choice Questions & Answers (MCQs) focuses on “Cores and Types”.
1. __________ is also termed as an obstruction when positioned in the mould.
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 ___________
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 ________________
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.
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.
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
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.
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.
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
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
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.
Sanfoundry Global Education & Learning Series – Foundry and Forging.
To practice all areas of Foundry and Forging, here is complete set of 1000+ Multiple Choice Questions and Answers.