Tool holder

摘要

A chuck for rapid fitting of a hard metal boring tool has a rectangular end to the shaft of the tool and with a recess which is gripped by a radially acting retaining slug (6). The slug is pressed into the grip by a sleeve of the chuck. It replaces the grip ball of conventional chucks which rely on their grip by pressing into the shaft of the tool. The recess can be provided by a transverse groove and the tip of the slug is shaped to drop into the recess. The bottom end of the borer shaft is chamfered to rid over the slug.