CNC (Computer Numerical Control) machining refers to a manufacturing process in which a control system issues commands to drive cutting tools through specific, required movements, executing operations based on technical specifications-such as workpiece shape and dimensions-and processing requirements expressed in numerical and alphanumeric formats. Broadly speaking, it encompasses the entire process of machining parts using CNC machine tools.
A CNC machine tool is a machine controlled by a computer; the computer governing the machine-whether a dedicated unit or a general-purpose one-is collectively referred to as the CNC system. Both the primary movements and auxiliary actions of the machine tool are governed by commands issued by the CNC system. These commands are programmed by a human operator based on factors such as workpiece material, machining requirements, machine characteristics, and the system's specific command format (CNC language or symbols). The CNC system interprets these program commands and sends operational or termination signals to servo units and other functional components to control the machine's various movements. The machine stops automatically once the part machining program concludes. No CNC machine tool can operate without program commands being input into its control system. Controlled machine actions generally include starting and stopping the machine; controlling the spindle (start/stop, rotation direction, and speed changes); managing feed motion (direction, speed, and mode); handling tool selection and compensation (length and radius); and managing tool changes as well as the activation and deactivation of coolant.
