Abstract:To subgrade the shape-curve roughness of a contact roller,the three-coordinate CNC milling machine has been enlarged as a CNC lathe and CNC grinding machine so that the contact rollers can be lathed and grinded by the same installation and NC program. Furthermore,an NC program of dealing with complex curve contact rollers has been developed. Acceptable metal shaving contact rollers of cycloidal gears and involute gears in shape grinding have been manufactured with this method.