NC code

NC (numerical control) code is the machine-readable program, most commonly in G-code format, that instructs a CNC machine's controller exactly how to move: which axis, how far, how fast, and when to turn a spindle or coolant on or off. It is the direct output of CAM, adapted for a specific machine and controller by a postprocessor.

Why NC code isn't universal across machines

NC code is machine-specific: the same toolpath produces different NC code for different machine controllers, which is why a postprocessor exists to translate a generic CAM toolpath into the exact syntax a specific machine understands.

Where NC code comes from

Not on the drawing; NC code is generated from the CAM toolpath and is specific to the machine that will run the program, not part of the technical documentation.

Common mistakes

Assuming NC code generated for one machine will run correctly on a different machine or controller without adaptation via a postprocessor.

Is NC code the same as G-code?

G-code is the most common format of NC code; NC code is the broader term for machine-readable CNC instructions.

Who or what generates NC code?

CAM software generates the initial toolpath, and a postprocessor translates it into the specific NC code syntax a given machine's controller requires.

Can the same NC code run on any CNC machine?

No, NC code is specific to a machine's controller; running it on a different machine typically requires regenerating it through the correct postprocessor.