Question 3
3. (a) (i) Sketch a buttress thread;
(ii) Label four parts of the sketch in 3(a)(i).
(b) Explain the following foundry terms:
(i) core print;
(ii) cavity.
Observation
The part (b) of this question seems difficult for the candidates, as only about 5% of them got it correctly. The required response to this part is as follows:
(b) Core print: it is a small projection at the end of patterns which provide recesses for accommodating cores in the mould.
Cavity: it is an opening created by the pattern in the sand to allow molten metal to take the form of the finished product.