... 1, all made by advanced CNC lathe, pass ISO, ANSI,DIN quality certification. high precision and good wear resistance. 2 ... to the customer drawings) and standard(the metric system) sprockets 5, extensive use: machinery, metallurgy, mine, build, electron, port etc ... plastic bag and outer carton box or customer requirement. ANSI C45 industrial machining hard teeth transmission chain drive black oxide ...