... packing poly bag carton material: Carbon steel, Alloy steel, stainless coach screw bolt:M3-M22*length5mm~160mm nut:M3-M30 Washer ... :M3-M30 coach screwStandard:GB,DIN,ASME,BSW,UNC,JISGread:Gr1,Gr2,Gr3 ... , stainless steel. Believe us,choose us.Time will tell everything. Coach Bolt DIN603