CNC machining is the manufacture and processing of parts and products under computer control.

Processing adjustments are made to a piece of material (i.e., a workpiece) by automatically removing excess parts of the material. Typically, the material used is metal, and after removal, the finished product or part has already been produced. This process is also known as subtraction manufacturing.

In order to better carry out CNC machining, computer applications control machine tool movements. The types of machining processes commonly used on CNC machines include the most common types of milling and turning, followed by grinding and electrical discharge machining. During milling operations, a rotating tool is used on the workpiece surface to move along three, four, or five axes. Basically, cutting or trimming the workpiece can quickly process complex geometric shapes and precision parts from metal. In turning work, a lathe is used to manufacture parts that contain cylindrical features. The workpiece rotates on the shaft and comes into contact with precision turning tools, forming circular edges, radial and axial holes, grooves, and grooves.

Compared with traditional manual machining, CNC machining is much faster, and the computer code is correct and in accordance with the design. The finished product has high dimensional accuracy and small error. CNC manufacturing can be used to manufacture end-use products and components, but it is generally cost-effective only in short-term production operations with low volume, so it is an ideal rapid prototyping manufacturing method.