Q. The maximum reduction in cross-sectional area per pass ( R ) of a cold wire drawing process is
R = 1 –e-(n+1) ,
where n represents the strain hardening coefficient. For the case of a perfectly plastic material, R is
(A) 0.865 (B) 0.826 (C) 0.777 (D) 0.632
Ans: 0.632
