Cold-headed and roll-formed pick type cutter body with carbide insert

摘要

A pick type bit is disclosed with an improved socket for a carbide insert. The cutter body of the bit is cold-headed from a steel blank to provide a cylindrical shank and a conical head with a socket in the forward end. The cylindrical shank is roll-formed to provide a retaining groove and an intermediate section is roll-formed to provide an extraction groove between the head and the shank. The cold-heading includes an initial step of squaring-up the forward end of the blank by cold-heading it into cylindrical shape with a flat forward end and then punching the socket. This provides a socket of densified work-hardened steel. The bit is completed by brazing the base of a carbide insert in mating relation with the socket in the head.