Nitriding heat treatment is one of several surface hardening heat treat processes. Nitriding diffuses nitrogen into the surface of certain metals creating a hard surface more resistant to wear and corrosion. Low-carbon, low-alloy steels are often nitrided but it is also possible to nitride titanium, moly, aluminum and some medium and high-carbon steels. Most often, high-wear parts like gears, crank- and camshafts are nitride. Extrusion or forging dies are also frequently nitrided. Other hardening heat treatments competitive with nitriding are carburizing, nitrocarburizing and ferritic nitrocarburizing (FNC).