... ,etc. Material: 45#, 40Cr, 42CrMo(B7), etc. Finish: Plain, Black, Zinc, H.D.G., etc Specification: ASTM A 194/A 194M ... -Carbon and Alloy Steel Nuts for Bolts for High pressure or High Temperature Service, or ... ,etc.Material: 45#, 40Cr, 42CrMo(B7), etc.Finish: Plain, Black, Zinc, H.D.G., etc. Heavy hex nuts and heavy hex jam nuts