Patent ID: 7510032

Claim:
A hard composite cutting insert having a top end and a bottom end and a peripheral surface, the hard composite cutting insert comprising: a matrix region, and a portion of the matrix region defining a first section of the peripheral surface; the matrix region containing an embedded member wherein a portion of the embedded member defining a second section of the peripheral surface, and the first section of the peripheral surface is larger than the second section of the peripheral surface at the top end of the insert; and the matrix region being made from a first composition and the embedded member being made from a second composition wherein the first composition having a toughness greater than the toughness of the second composition and the second composition having a hardness greater than the hardness of the first composition and: (a) wherein the matrix region comprises between about 6 weight percent and about 25 weight percent cobalt and between about 75 weight percent and about 94 weight percent tungsten carbide; and the average grain size of the tungsten carbide ranging between about 3 microns and about 15 microns; and (b) wherein the embedded member comprises between about 6 weight percent and about 25 weight percent cobalt and between about 75 weight percent and about 94 weight percent tungsten carbide; and the average grain size of the tungsten carbide ranging between about 1 micron and about 15 microns.