Nitrocarburizing is a variation of the nitriding process. It is a thermochemical diffusion process where nitrogen, carbon, and to a very small degree, oxygen atoms diffuse into the surface of the steel part, forming a compound layer at the surface, and a diffusion layer. Nitrocarburizing is a shallow case variation of the nitriding process. Advantages of the process include the ability to harden materials which are not prehardened, the relatively low temperature of the process which minimizes distortion, and relative low cost in comparison to carburizing or other case hardening processes. This process is done mainly to provide an anti-wear resistance on surface layer and to improve fatigue resistance.