Question

In order the get a smooth casting, the size of the sand particles should be _________

(a) Coarse

(b) Fine

(c) Moderate

(d) Large

The question was posed to me in an online interview.

Question is from Properties of Moulding Sand topic in section Pattern Materials & Moulding Sand Tests of Foundry and Forging

Answer 1

Correct choice is (b) Fine

To explain I would say: The fine grains are the sand particles which has a lower grain size. This lower grain sized particles always form a smooth surface over which the curves and edges can be dimensionally mapped. The fine particles allow less distortion of the metal and the surface obtained by them on the casting is smooth.