ROTARY CUTTING BIT WITH MATERIAL-DEFLECTING LEDGE

摘要

A cutting bit includes a body having a front surface and a side surface, th e side surface including a shoulder below the front surface and extending substantially perpendicular to a central axis of the body, and a ring that i s harder than the body attached to the body at a front surface of the shoulder . Wear life of the cutting bit is enhanced by maintaining particular dimension al relationships regarding the position of the ring on the body, and the diamet er of portions of the body.