Boring tool for drilling through holes - has cutting edges on end face and hollow shank leaving solid core which drops out on completion of hole

摘要

A boring tool has a shank (4) with a central bore (3). The end face of the tool has a number of cutting edges or inserts (1) whilst the lower part of the shank has flutes for removing the metal chips. This boring tool is intended for drilling through holes and only cuts out a metal shell with the core of the material removed from the workpiece going into the central hole (3) of the tool. There is thus less wear on the cutting edges and in addn. less power is needed to drill holes compared with conventional drills.