Size: 1/2" - 4" Grade: 2H,2HM,4,7,7M,etc. Material: 45#, 40Cr, 42CrMo( ... ., 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 B 18.2.4.6MSize: 1/2" - 4"Grade: 2H,2HM,4,7,7M ... ), etc.Finish: Plain, Black, Zinc, H.D.G., etc. Heavy hex nuts and heavy hex jam nuts