The relationship between metal-induced chemical bonding and the mechanical properties of Me/a:C-H (Me- Ti and Ni) films are discussed. Nanocomposite films were deposited onto the Si substrates via biased target ion beam sputtering of metal combined with reactive ion beam deposition of a:C-H using CH4/Ar gas mixture. The chemical composition, microstructure and mechanical properties were characterized using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and nanoindentation. XPS analysis revealed that both Ti and Ni atoms were preferentially bonded to carbon to form its metal carbide phase. Irrespective of its kind, both the metal carbide clusters induces more graphite like bondings in a:C-H matrix. From the nanoindentation analysis it was found that there is no crack propagation and damage around the indent region even at very high indentation loads. Additionally, it was found that a:C-H film shows higher hardness compared to that of Ti/a:C-H and Ni/a:C-H films.