Nickel micro-gears were fabricated using optical projection lithography on copper-clad plastic substrates and nickel electroplating. Adopting low numerical-aperture projection exposure, large depth-of-focus was secured, and SU-8 resist moulds with vertical sidewalls were fabricated. In addition, cost was greatly reduced by using copper-clad plastic substrates instead of silicon wafers. After nickel was electroplated in nickel sulfate solution, nickel gears with modules of 0.026–0.04 and pitch diameters of 760–1100μm were stripped from the substrates when the resist moulds were dissolved in hot remover.