Carbonitriding heat treatments are similar to carburizing, but the furnace atmosphere imparts nitrogen as well as carbon to the steel surface.  The result is a higher hardness surface microstructre with greater wear resistance than with straight hardening or carburizing.  The most common carbonitriding applications are found in stampings, bearings, self-tapping fasteners, and in screw machine parts made from low hardenability core materials.  Carbonitriding heat treatments are typically performed in both batch and continuous furnaces, depending upon the size and geometry of the parts and upon the case depth specification.