... ANSI,DIN type 2,high precision cnc tech 3,black oxide anti-corrosion 4,large production, ... treatment is black, galvanization, chroming and colored drawing. 3, material is A3\C45, stainless steel and customer ... the customer drawings) and standard(the metric system) sprockets 5, extensive use: machinery, metallurgy, mine, build, electron ... . ANSI machine black oxide sprocket/hard teeth drive sprocket