A cold heading operation is performed to produce the head on a steel nail. The strength coefficient for this steel is 600MPa, and the strain hardening exponent is 0.22 . Coeff. of friction at die work interface is 0.14 The wire stock out of which the nail is made is 5 mm in diameter. The head is to have a diameter of 9.5 mm and a thickness of 1.6mm. The final length of nail is 120 mm.
(a) What length of stock must project out of the die in order to provide sufficient volume of material for this upsetting operation?
(b) and what is max force that the punch must apply to form the head in this open die operation?