1.Surface:black,phosphated,galvanized..
2.Grade:4.8,8.8,10.9,12.9
3:Material:mild steel,45# steel,40Cr,42CrMo
high strength hex bolt, hex cap bolt, balck bolt1. Surface:black oxide, phosphated,galvanized, Dacrotized 2. Grade:4.8, 8.8, 10.9, 12.9 3. Material: mild steel, 45#...