Welding and Fabrication Eng. Craft Practice 2, WASSCE (SC), 2016

Question 4

(a)        What is hardening?


(b)        Explain the following forging processes:
(i)         twisting;
(ii)        drawing down.
(c)        With the aid of a sketch, describe how to form a bend over an anvil.

Observation

Most of the candidates who attempted this question had difficulty in explaining twisting and drawing down. The correct responses are:


Twisting: It is a process of turning a work piece either hot or cold.  It involves
heating the section to be twisted evenly along the length and turning using both hands with a tap wrench or a bar with square or rectangular hole at the centre.

 

Drawing down: It is a process in which the cross section of a work piece is
reduced and its length increased.  This is done by hammering the heated work piece.