Patent ID: 8580406

Claim:
A die for cold plastic working comprising a material comprising a substrate and a hard coating film formed on a surface of the substrate and formed by a cathode arc ion plating method, wherein the hard coating film comprises (Nb x M 1-x ) y (B a C b N 1-a-b ) 1-y , wherein 0.2 ≦x< 1.0 Equation (1) 0 ≦a≦ 0.3 Equation (2) 0≦1- a - b≦ 0.5 Equation (3) 0.5 ≦b≦ 1 Equation (4) 0.4≦1- y≦ 0.9 Equation (5) wherein, M denotes V only, or V and at least one species of elements belonging to Groups 4a, 5a, which are different from V, and 6a and Si and Al; x, 1-x, a, b, and 1-a-b represent respectively the atomic ratio of Nb, M, B, C and N; y and 1-y represent respectively the ratio of (Nb x M 1-x ) and (B a C b N 1-a-b ): when M comprises Al, then 0.5≦x<1.0, wherein 0.1≦a≦0.3.