Patent ID: 6890632

Claim:
A cutting tool insert comprising a cemented carbide body and a coating, the body having a composition comprising 8.0-8.5 wt % Co, 0.5-2.1 wt % of a total amount of cubic carbides of the metals Ta and Nb, the ratio of the weight concentrations of Ta to Nb is 1.0-12.0, and balance WC, with a mean intercept length of 0.4-0.9 μm, and the binder phase being alloyed with W corresponding to an S-value of 0.82-0.94, and said coating comprises a first, innermost layer of TiC x N y O z with 0.7≦x+y+z≦1, with equiaxed grains and a total thickness <1 μm, a second layer of TiC x N y O z with 0.7≦x+y+z≦1, with a thickness of 0.5-7 μm with columnar grains, at least one layer of Al 2 O 3 primarily composed of the κ-phase and having a thickness of 0.2-5 μm.