Patent ID: 7993742

Claim:
A cutting tool insert comprising a substrate at least partially coated with a coating having a total thickness of from about 5 to about 40 μm, comprising one or more refractory layers of which at least one layer of which is an {acute over (α)}-alumina layer wherein said {acute over (α)}-alumina layer comprises nucleated columnar {acute over (α)}-Al 2 O 3 grains with a <001> growth direction with texture coefficients a) TC(006)>1.4, the texture coefficient TC(hkl) being defined as TC ⁡ ( hkl ) = I ⁡ ( hkil ) I 0 ⁡ ( hkil ) ⁢ { 1 n ⁢ ∑ I ⁡ ( hkil ) I 0 ⁡ ( hkil ) } - 1 wherein I(hkl)=measured intensity of the (hkl) reflection I 0 (hkl)=standard intensity according to JCPDS card no 46-1212 n=number of reflections used in the calculation (hkl) reflections used are: (012), (104), (110), (006), (113) and (116).