It is required to produce a rod of 22 mm diameter and 200 mm length from original one of 40 mm diameter using extrusion process, where the extrusion ratio is 1.6 and the material mechanical behavior is a=30004 MPa, if the yield occurred at 0.2 strain and the fracture occurred at 0.7 strain, where, (a=0.8, b = 1.3) Calculate: 1- Number of stages. 2- The total plastic work. 3- The maximum extrusion pressure. 4- The maximum extrusion force.