Bolt Features: 1) spec:DIN931,DIN933,DIN85 2) Grade: 4.8, 6.8, 8.8, 10.9, ... according to customers' order3) Materials: carbon steel, alloyed steel4) Grade: 4.8, 6.8, 8.8, 10.9, 12. ... plating, nickel plating, heat refining, surface darkening6) Hexagon bolt producing technological process: parcel-anneal-pickling-cold drawing-cold upsetting ... keep improvine our company and developing our business. Bolt