Forging is a long-practiced metal forming process that shapes metal by applying high forces. The application of forces to form metal into the desired part actually strengthens the metal part as the metal grains deform in a phenomenon known as work hardening. Work hardening does not occur in other common metal processes such as casting, machining, or metal sintering, giving an advantage to parts made via forging. Forging can be done at a wide range of temperatures. Forging processes that occur below or near room temperatures are referred to as cold forging, and as temperature increases, the process is instead called warm forging or even hot forging at the highest forging temperatures.