Computer numerical control uses programmed instructions to dictate the exact movements of machine tools like mills and lathes. The controller reads code to drive motors, moving cutting tools along multiple axes with extreme precision. This automation replaces manual handwheels and allows shops to produce complex or repetitive parts rapidly.
Load the bar stock and let the CNC run that batch of spacers while we set up the manual mill.
Even though CNC implies the entire machine, machinists often use it as a noun to distinguish automated equipment from manual machines.
Related terms
Machining center
An automated, computer-controlled machine tool capable of performing multiple milling and drilling operations.
VMC
Vertical machining center, a computer-controlled milling machine with a vertical spindle.
HMC
Horizontal machining center, a CNC mill with a horizontal spindle.
Toolpath
The exact geometric route a cutting tool follows to shape a part.