Patent ID: 8283058

Claim:
Cutting tool insert comprising a substrate and a coating, wherein the substrate comprises WC with a grain size of from about 0.4 to about 1.0 μm, from about 5 to about 8 wt % Co, Cr such that a Cr/Co-ratio by weight is from about 0.05 to about 0.15, and ppm levels of Ta, Ti, or mixtures thereof, present in such amounts that a ratio Me/Co=(at-% Ti+at-% Ta)/at-% Co is lower than or equal to about 0.014−(CW_Cr)*0.008 and higher than about 0.0005, and CW_Cr is from about 0.75 to about 0.95, wherein CW_Cr=(magnetic-% Co+1.13*wt-% Cr)/wt-% Co, wherein magnetic-% Co is the weight percentage of magnetic Co, wt-% Cr is the weight percentage of Cr and wt-% Co is the weight percentage of Co in the cemented carbide, and the coating is a PVD Ti x Al 1-x N-coating, with an average composition of x being greater than about 0.4 but less than about 0.9, present as a single or multilayer coating with a total thickness of greater than about 1 μm, but less than about 6.0 μm.