We have deposited thick SiC thin films on graphite substrates in the temperature range of 700-850 degrees C using single-molecular precursors by both thermal metal-organic chemical-vapor deposition (MOCVD) and plasma-enhanced MOCVD (PEMOCVD) methods for oxidation-protection wear and tribological coating. Hexamethyldisilane (HMDS), (CH3)(3)Si-Si(CH3)(3), was used as a single-source precursor, and hydrogen and Ar were used as a bubbler and carrier gas. A highly oriented polyerystalline cubic SiC layer in the [111] direction was successfully deposited on graphite at temperatures as low as 800 degrees C with HMDS by PEMOCVD. For thermal MOCVD, on the other hand, only amorphous SiC layers were obtained at 850 degrees C. From this study, we confirmed that PEMOCVD was a highly effective process in improving the characteristics of the SiC layers compared to those grown by thermal MOCVD. The mechanical and oxidation-resistant properties have been assessed. The optimum SiC film was obtained at 850 degrees C and rf power of 200 W. The maximum deposition rate and microhardness are 2 mu m/h and 4336 kg/mm(2) Hv, respectively. The hardness was strongly influenced by the composition ratio of the SiC protective layers.