The punch speed should be chosen to make sure that the dynamic effect of the deformable body is within a reasonable range. Generally speaking, the final kinetic energy of the blank should be less than 5% of the internal energy. Even in the initial contact stage, the kinetic energy should not exceed 10% of the internal energy. Usually the peak punch (or the primary moving die member) speed is chosen to be in the range of 1m/s—5m/s.