... type 2,high precision cnc tech 3,black oxide anti-corrosion 4,large production, large stock Sprocket 1, all made by ... MaterialC45, A3, 40Cr, 20CrMnTi, 42CrMo, copper, stainless steel and so on as per your requestprocessForged or castingHeat treatmentHigh frequency quenching, heat ... plastic bag and outer carton box or customer requirement. weld on sprocket