Machining is the process to shape any raw material (workpiece), metal or nonmetal, into a part (product) or to improve the tolerance and surface finish of a previously formed workpiece by removing a portion of the raw material. This can be done either mechanically (turning, drilling, milling, grinding, water-jet machining, ultrasonic machining, etc.), chemically (chemical machining, electrochemical machining, etc.), electrically (electrical discharge machining), or thermally (laser machining, electron beam machining, etc.).