To provide a surface coated cutting tool having a hard coated layer exhibiting excellent wear resistance in high speed cutting for highly reactive material to be cut.
In this surface coated cutting tool, a hard coated layer including the followings is formed on the surface of cemented carbide base or on the surface of high speed tool steel base by vapor deposition: (a) an upper layer and a lower layer, which are both formed of (Ti, Al, Ta)N, the upper layer has an average layer thickness of 0.5 to 1.5 μm and the lower layer has an average layer thickness of 2 to 6 μm; (b) the upper layer has an alternately stacked layer structure of a thin layer A and a thin layer B, both of which have an average layer thickness per layer ranging from 5 to 20 nm, the thin layers A, B are respectively formed of (Ti, Al, Ta) N layer satisfying a specific composition formula; and (c) the lower layer is formed of (Ti, Al, Ta) N layer having a single phase structure and satisfying the formula [Ti1-(X+Y)AlXTaY]N (wherein by atomic ratio, X is 0.50 to 0.65 and Y is 0.01 to 0.10).
TANAKA YUSUKE
MITSUBISHI MAT KOBE TOOLS CORP
Kutaro Kamoi
Kageyama Shuichi