... .8,10.9,12.9 3:Material:mild steel,45# steel,40Cr,42CrMo high strength hex bolt, hex cap bolt, balck bolt1 ... :4.8, 8.8, 10.9, 12.9 3. Material: mild steel, 45# steel, 40Cr, 42CrMo4. Packing: standard neutral carton box ... ) Strict quality control(3) very reasonable and competitive price high strength black bolt