The velocity vectors in the flash and body of a press forging of commercially pure lead having axial symmetry were obtained experimentally from incremental displacements in stepwise forging operations. It was found that the velocities are in excellent agreement with those derived with the aid of a simple disk theory, where it was assumed that all deformation is concentrated in a fictitious disk. Comparison with velocities derived from certain slip-line solutions also shows that substantial agreement exists here between theory and experiment.
Calculated average forging pressures, which were obtained by the approximate disk and slip-line theories, are in approximate agreement and the local pressure distributions are similar. These results seem to clarify the role which the flash height and friction in the die-lands play in achieving a good impression of the die cavities.