Hammer drill bit - has cruciform cutters with notches in two opposite ones

摘要

The hammer-drill bit is for use in rock or concrete. it has four radial cutters (5) on radial arms on a cemented-carbide cruciform insert, together with a centring tip (4) protruding above the cutters. Two cutters on opposite sides of the tip are each interrupted by one or more notches (6) betwen the tip and the peripheral portion (8). The other two cutters are continuous, with no notches. ADVANTAGE - Long life and fast working.