1.Size:M1.6-M100 2.Length:5-650mm 3.Grade4.8/8.8 A2,A4 4.carbon/mild/stainless steel... high strength hex bolts fasteners 1.Size:M1.6-M1002.Surface:black,phosphated,galvanized.. 3:Material:mild steel,45# steel,40Cr. High strength hex bolts fasteners(1)Grade4.8/8.8 A2,A4 (2)Surface:Black, phosphate, hot dip galvanized(3) Material:20MnTiB, 40CR(4)High strength bolts are widely used in industry, ...