Patent ID: 8133598

Claim:
A hard coating film formed on the surface of a substrate, wherein the hard coating film is represented by the formula: (Ti a Cr d Al b Si c )O x wherein 0.05≦a≦0.4 0.1≦d≦0.85 0.1≦b≦0.7 0≦c≦0.2 a+b+c+d=1 0.8≦[x/(2a+1.5d+1.5b+2c)]≦1.2 where variables a, d, b, and c denote the atomic ratios of Ti, Cr, Al, and Si respectively, and variable x indicates the atomic ratio of O, wherein the substrate is a substrate of a member selected from the group consisting of cutting tools, metal dies, jigs and plastic metal working tools.