The kinetic energies of the crank mechanism and anvil and flash material are considered in order to develop a relation between forging load and the velocity of the upper die. Theoretical results are compared with published data. The dynamics of flash formation are also considered. When a larger flywheel is used, forging loads may be calculated in terms of the changes in energy of the flywheel. Hence, the ratio of press capacity to forging load is an important factor in the mechanics of forging.