Extractable screw or bolt head manufacturing method, involves producing tapered recesses at large quantities with embossments including embossment punches by using embossment transfer machine

摘要

The method involves producing tapered recesses at large quantities with embossments including embossment punches by using an embossment transfer machine. One of the punches is lowered to a level of a lower face of a mark to be realized on a head of a screw or bolt, where the punch includes a relief on a lower face of the punch corresponding to bottom of a groove. The punch has cuts (2) that are slanted on their external surfaces and vertical on their internal surfaces. The other punch is lowered at a level of an exterior surface of the head of the screw or bolt.