Patent ID: 8053063

Claim:
A cutting tool insert, comprising: a cemented carbide body; and a coating; wherein said body has a composition comprising: about 9.3-10.9 wt% Co; about 0.5-2.5 wt% of metals selected from the group consisting of Group IVb metal, Group Vb metal, Group VIb metal, and combinations thereof; and balance WC; wherein said body has a coercivity of about 10-15 kA/m, and an S-value of about 0.81-0.95; and wherein said coating consists of: a first (innermost) layer of TiC x N y O z , with 0.7≦x+y+z≦about 1, with equiaxed grains and a total thickness<about 1 μm; a second layer of TiC x N y O z with 0.7≦x+y+z≦about 1, with a thickness of about 1-5 μm with columnar grains; and an outer layer of strongly textured Al 2 O 3 consisting of an α-phase with a thickness of about 1-5 μm.