CNC is a subtractive manufacturing method that leverages a combination of computerized controls and machine tools to remove layers from a solid block of material. The desired cuts in the metal are programmed according to corresponding tools and machinery, which perform the machining task in an automated fashion.
The systems used in CNC milling operations are known as CNC milling machines. They can have a moving workpiece and a stationary rotary tool, a stationary workpiece and a moving rotary tool, or a moving workpiece and rotary tool, depending on their design and the milling requirements. As CNC milling generally serves as a secondary or finishing process for machined components, milling machines can be used to create design elements such as flat surfaces, contours, grooves, slots, notches, holes, and pockets.