Being extremely small and with high amount of surface atoms, nanodiamond has diversified applications. Some applications involve using the superhard properties of diamond. The others may adapt low frictional coefficient of diamond. Nanodiamond can reduce significantly the frictional coefficient by coating on the sliding surface. The nanodiamond coating reduces the contact area. Moreover, the inertness of the diamond surface reduces the atomic drag force across the interface of the two relatively moving surfaces. Nanodiamond used as engine oil additive have demonstrated reduced gasoline consumption and increased engine life. These benefits are attributed to the coating of nanodiamond on the walls of the cylinder. As a result, the frictional coefficient is reduced. The electroplating of metal coating using electrolyte with nanodiamond dispersion allows the impregnation of nanodiamond. However, the incorporation may be small due to the Brownian motion of the nanodiamond in the liquid medium. The incorporation of nanodiamond can be boosted by electrophoresis with charged nanodiamond in electrolyte.