Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) on “Finishing Patterns & Storing of Patterns”.
1. Finishing allowance to a pattern is generally provided to avoid various defects in the casting.
a) True
b) False
Answer: b
Clarification: Finishing allowance is generally provided for a machining process, the finish and accuracy achieved in sand casting are usually poor and therefore when the casting is functionally required to be of better surface finish, so the machining is required that is accomplished by providing finishing or machining allowance.
2. Finishing also includes removal of scales from the surface of the casting.
a) True
b) False
Answer: a
Clarification: When the casting is made in the mould cavity, some of the oxides layers called as scales adhere tightly to the surface of metal casting, which should be removed for making casting strong and durable. So to achieve this, proper finishing and cleaning are done with the help of tools to make casting free from scales.
3. Subsequent machining for products finishing does not require extra material to the metal casting, as it removes negligible amount of material from the casting.
a) True
b) False
Answer: b
Clarification: It is very necessary to include extra material to the metal casting to compensate it for subsequent machining which removes very fine particles to vanish roughness and to make casting smooth and aesthetically pleasant. Then the casting becomes ready for industrial application.
4. Which of the following ranges show the approx range of finishing depth (in mm) required for finished casting?
a) 2 to 20
b) 20 to 30
c) 30 to 35
d) 35 to 40
Answer: a
Clarification: The range of finishing depth basically depends on dimensions, the type of casting material and the surface finish required, but for the approximation, it comes in the range of 2 to 20 mm. In this range, casting can achieve greater surface smoothness and shiny surface with good appearance.
5. For finishing allowance, great care is taken while adding extra material to the molten metal.
a) True
b) False
Answer: a
Clarification: After extraction of casting from the mould cavity, the finishing allowance provided would ultimately have to be removed by machining. Hence, great care is taken while adding extra material as to maintain the cost of material. So it is always examined before finalizing for the production of casting.
6. Which of the following parts is used to keep the casting in for reducing the finishing allowance?
a) Centrifuge
b) Burette
c) Drag flask
d) Conical flask
Answer: c
Clarification: In finishing allowance, the entire casting is put in the drag flask to reduce the finishing allowance such that the dimensional variation and other defects due to the parting plane are reduced to a minimum. This part is widely used in the casting process to make the casting economical and sustainable.
7. Which of the following technologies is used in metal casting for reducing the product development time?
a) Radiography
b) UV radiation
c) Eddy current coiling
d) Rapid prototyping
Answer: d
Clarification: Rapid prototyping is used for decreasing the product development time in metal casting, in which parallel horizontal layers of material are formed with the help of equidistant layers in a computer through CAD software. This all is achieved by rapid prototyping without application of any finished pattern.
8. After providing the finishing allowance to the metal casting, it is not necessary to include shake allowance as it can be covered by finishing allowance.
a) True
b) False
Answer: b
Clarification: The purpose of shake allowance is totally different and opposite from finishing allowance. Shake allowance includes reducing of pattern dimensions, before implementing this, the casting made is generally large that is caused by the pattern removal which enlarges the mould cavity. So, shake allowance is provided, it is also called a negative allowance.
9. A Fillet is provided in the finishing of a pattern which is very small for shallow castings.
a) True
b) False
Answer: a
Clarification: Intersecting surfaces forming junctions of metal thickness are usually joined with fillets in order to avoid high stress concentrations in the metal casting. Shallow castings commonly have much smaller fillets, while the deep pockets and other interior complex corners may have larger fillets.
10. In finishing of a pattern, fillets are provided to eliminate the stresses completely from the metal casting.
a) True
b) False
Answer: b
Clarification: Stresses cannot be eliminated completely, only it can be reduced or distributed to the more part of the material. Fillet Radius makes the casting stronger because it redirects stresses from being concentrated at a sharp internal corner and distributes them over the broader volume of the fillet material.
11. Why is it important to take careful measurements/steps while storing the pattern?
a) They loose their shape and size
b) They get rusted
c) They get warped
d) All of the mentioned