Patent ID: 9724763
Date: 2017-08-08
CPC Classifications: B23B,Y10T

Claim:
1. A bit for a rotary drill, the bit including a cylindrical body having at least two flutes provided therein, the cylindrical body terminating in a cutting end; and a cylindrical land defined by a peripheral face of the cylindrical body between adjacent flutes, the cylindrical land including a margin that is radially elevated relative to a remainder of the cylindrical land; the margin having a width that varies along the length of the cylindrical land and including a wide zone and a narrow zone, the wide zone being located towards the cutting end of the drill and adjacent a cutting edge of the drill, wherein a point of the drill includes a polycrystalline diamond (PCD) volume in the form of a PCD layer, wherein the wide zone of the margin is at least partially defined by the PCD layer, and wherein the PCD layer covers the entire cutting point.