sprocket 1,25b-120b all type 2,high precision cnc tech 3,black oxide anti-corrosion 4,large production, large ... stock Black Oxide Sprocket 1, all made by advanced CNC lathe, pass ISO, ANSI,DIN quality certification. high precision and ... and outer carton box or customer requirement. ANSI C45 industrial machining hard teeth transmission chain drive black oxide sprocket wheel