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