Metal fabrication requires the machinery used to be controlled accurately by strictly having full control over the movement of the part, the cutting head, and other things like the speed of the spindle.

In CNC machining, all these controls are through the use of a code that has control over the machinery that is being used. Machining is a subtractive method of fabrication that requires material from the part to be removed to form the desired shape. This method, CNC or computer numerical control, uses digital files that have the instructions needed for tooling and cutting trajectories.

Prior to the machining, the parts are designed with CAD software that determines the properties and dimensions of the part. CAM software is used to prepare the model generated in CAD for the process of fabrication. This program creates a set of coordinates that guide the cutting during the manufacture of the part.