... , 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 BothDimensions: ANSI B 18.2.2 and ANSI ... ,4,7,7M,etc.Material: 45#, 40Cr, 42CrMo(B7), etc.Finish: Plain, Black, Zinc, H.D.G., etc. Heavy hex nuts and heavy hex jam ...