In developing a TiN coating for cobalt cemented WC–TiC–TaC tools, the effect of TiCl4 partial pressure in an H2+N2 atm was studied over the range of approximately 0.03–0.30 atm. The two temperatures of deposition studied were 1000 and 1080 °C. Low TiCl4 partial pressure combine to produce columnar grains > 10 μ in length and faster coating rates. Higher TiCl4 partial pressures in the range of 0.05–0.10 atm produce random oriented grains of approximately 1 μ or less and slower coating rates. TiCl4 pressures greater than 0.30 atm at 1000 °C nearly stop deposition of TiN. The TiN coating is especially useful in minimizing wear on carbide cutting tools.