8.6 In a particular piercing operation, 20 mm holes are to be punched in a brass sheet of 3 mm thick. The

maximum shear strength of the sheet may be taken as 185 MPa. Design the punch and the die sizes as

well as the required punch force.

8.7 A cylindrical cup, 100 mm diameter and 85 mm deep, is to be drawn from a steel sheet of deep

drawing quality, 1 mm thick. Determine the blank diameter and the other drawing variables for the

dies of all draws. Also, estimate the drawing load if the tensile strength is 415 MPa.