Question

______________ is used to reduce the chances of damaging the mould cavity.

(a) Draft Allowance

(b) Shrinkage Allowance

(c) Finish Allowance

(d) Machining Allowance

The question was asked in an international level competition.

My question is from Patterns and its Functions in portion Casting Processes of Foundry and Forging

Answer 1

Right answer is (a) Draft Allowance

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.