ar Stress As shown in the figure below, a hole is to be punched out of a plate having an ultimate shear stress of 300 MPa. (a) If the compressive stress in the punch is limited to 400 MPa, determine the maximum thickness of plate from which a hole of 100 mm in diameter can be punched. (b) If the plate is 10 mm thick, compute the smallest diameter hole which can be punched