METHOD OF MAKING STRETCHING PUNCHES Russian patent published in 1996 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of preparing beforehand a longitudinal cross framework, impregnating a sponge-type rubber with fluid thermosetting plastics by multiple compression of it and dipping into the thermosetting plastics, filling the framework by the impregnated sponge-type rubber; after the flowable thermosetting plastics had been hardened, performing an operation of shaping the punch by working it along its outer contour. EFFECT: enhanced quality of punches. 2 cl, 3 dwg