Metal Works 2, May/June 2015

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.

            (c)   State one quality of moulding sand.

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.