studs 1.Size:M16-72 2.Grade:10.9,8.8 3.Standard: GB898,GB899,GB900,GB901 4. Surface ... , Petroleum and Petrochemical field, etc.. hexagon bolt/high strength bolt1) Description: hexagon bolt/screw, hex bolt/screw, high strength bolts/screw2) Standard: GB898 ... : M16-M724) Surface: Zinc, HDG, DAC, Galvanized, Black, Plain5) Grade of strength: 10.9, 8.86) Materials: Alloy steel 42CrMo or B77) Packing ...