CNC Machine Codes

G-Code is one of a number of computer code languages that are used to instruct CNC machining devices what motions they need to perform such as work coordinates, canned cycles, and multiple repetitive cycles. The industry has standardized on G-Code as its basic set of CNC machine codes.

G-Code is the most popular programming language used for programming CNC machinery. Some G words alter the state of the machine so that it changes from cutting straight lines to cutting arcs. Other G words cause the interpretation of numbers as millimetres rather than inches. Some G words set or remove tool length or diameter offsets.

G-code (also RS-274), which has many variants, is the common name for the most widely used numerical control (NC) programming language. It is used mainly in computer-aided manufacturing to control automated machine tools. G-code is sometimes called G programming language, not to be confused with LabVIEW's G programming language.

G-code is a language in which people tell computerized machine tools how to make something. The "how" is defined by g-code instructions provided to a machine controller (industrial computer) that tells the motors where to move, how fast to move, and what path to follow. The most common situation is that, within a machine tool, a cutting tool is moved according to these instructions through a toolpath and cuts away material to leave only the finished workpiece. The same concept also extends to noncutting tools such as forming or burnishing tools, photoplotting, additive methods such as 3D printing, and measuring instruments.

List of G-codes commonly found on FANUC and similarly designed controls for milling and turning.

G-codes, also called preparatory codes, are any word in a CNC program that begins with the letter G. Generally it is a code telling the machine tool what type of action to perform, such as:

Rapid movement (transport the tool as quickly as possible in between cuts)

Controlled feed in a straight line or arc

Series of controlled feed movements that would result in a hole being bored, a workpiece cut (routed) to a specific dimension, or a profile (contour) shape added to the edge of a workpiece

Switch coordinate systems

Abbreviations used by programmers and operators

APC automatic pallet changer

ATC automatic tool changer

CAD/CAM computer-aided design and computer-aided manufacturing

CCW counterclockwise

CNC computer numerical control

CRC cutter radius compensation

CS cutting speed

CSS constant surface speed

CW clockwise

DNC direct numerical control ordistributed numerical control

DOC depth of cut

EOB end of block

E-stop emergency stop

EXT external

FIM full indicator movement

FPM feet per minute

HBM horizontal boring mill

HMC horizontal machining center

HSM high speed machining

HSS high speed steel

USB Universal Serial Bus

VMC . vertical machining center

VTL vertical turret lathe

Other Related Terms

3 axis cnc

5 axis cnc machine

5 axis cnc mill

5 axis cnc router

5 axis machining

cnc controller

cnc cutting

cnc cutting machine

cnc drilling machine

cnc grinder

cnc hobby

cnc lathe machine

cnc programming

cnc router machine

cnc simulator

cnc spindle

cnc step

cnc stock

cnc tools

cnc turning lathe

cnc turning machine

cnc vertical machining center

cnc wood carving machine

cnc wood cutting machine

cnc wood router

computerized numerical control

fanuc cnc

haas cnc

mazak cnc

Numerical Controlled Machine