Attributes . For Aluminum : Casting, Cast Iron, Low Carbon Steel : 1010, 1018, Medium Carbon Steel : 1035, 1045, High Carbon Steel : 1065, Alloy Steels : 4140, 4340, Die Steels : 20 HrC, Hardened Steels : 35 HrC, Hardened Steels : 35-45 HrC, Hardened Steels : 45-50 HrC . Names