Patent ID: 7820310

Claim:
A coated cutting tool insert having an upper face (rake face), an opposite face, and at least one clearance face intersecting said upper and opposite faces to define cutting edges, wherein said cutting tool insert is made of a cemented carbide or a ceramic substrate, said cutting tool coated with a hard layer system having a total thickness of from about 2 to about 50 μm and comprising at least one layer selected from titanium carbide, titanium nitride, titanium carbonitride, titanium carboxide, and aluminum oxide; an outer layer of an aluminum oxide, said outer layer being about 1 to about 15 μm thick; an outermost TiO x layer on the cutting edges and rake face, where x ranges from about 1 to about 2; a penultimate outermost TiO x layer on the clearance side; and an outermost TiC x N y O z layer on the clearance side, wherein x+y+z=1, x≧0, y≧0, and z≧0 and said outermost TiC x N y O z layer is from about 0.3 to about 2 μm thick.