... ,12.9 3:Material:mild steel,45# steel,40Cr,42CrMo high strength hex bolt, hex cap bolt, balck bolt1. Surface:black ... 40Cr, 42CrMo4. Packing: standard neutral carton box fastened with palltet5. Quality certificate:6. Supply ability: 1000 tons per month7. Selling points ... garantee:(1) Produce as per your request(2) Strict quality control(3) very reasonable and competitive price high strength black bolt