... tensile two head threaded stud bolts1) Material: High quality carbon steel Class :4.8, 5.8, 6.8, GR.2, A307 ... 2) Material :Alloy steel :20MnTiB ,40Cr ,42CrMo Class :8.8, 10.9,12.9 ... ,A325-1,A490-1 ,GR.B7,GR.B7M3) Material :stainless steel :302 ,304 ,305 ,316, 304L ,316L ,410, 430 Class: A2-50 ,A4 ... poly bag or plastic box. 3)As to customers' requirement stainless steel stud screw