CNC Programming G and M Codes Reference

A comprehensive list of G-codes, M-codes, and programming keywords for CNC tool motion and machine function control.

G00

Rapid move (not cutting)

G01

Linear move

G02

Clockwise circular motion

G03

Counterclockwise circular motion

G04

Dwell

G05

Pause (for operator intervention)

G08

Acceleration

G09

Deceleration

G12

Circular Pocket Milling Clockwise

G13

Circular Pocket Milling Counterclockwise

G17

x-y plane for circular interpolation

G18

z-x plane for circular interpolation

G19

y-z plane for circular interpolation

G20

turning cycle or inch data specification

G21

thread cutting cycle or metric data specification

G24

face turning cycle

G25

wait for input to go low

G26

wait for input to go high

G28

return to reference point

G29

return from reference point

G31

Stop on input

G33-35

thread cutting functions

G37

Tangential entrance

G38

Tangential exit

G40

cutter compensation cancel

G41

cutter compensation to the left

G42

cutter compensation to the right

G43

tool length compensation, positive

G44

tool length compensation, negative

G50

Preset position

G70

set inch based units or finishing cycle

G71

set metric units or stock removal

G72

indicate finishing cycle or 3D circular interpolation clockwise

G73

turning cycle contour or 3D circular interpolation counter clockwise

G74

facing cycle contour

G74.1

disable $360$ deg arcs

G75

pattern repeating

G75.1

enable $360$ degree arcs

G76

deep hole drilling, cut cycle in z-axis

G77

cut-in cycle in x-axis

G78

multiple threading cycle

G80

fixed cycle cancel

G81

drilling cycle

G82

straight drilling cycle with dwell

G83

drilling cycle or peck drilling cycle

G84

taping cycle

G85

reaming cycle or boring cycle

G86

boring with spindle off and dwell cycle

G89

boring cycle with dwell

G90

absolute dimension program

G91

incremental dimensions

G92

Spindle speed limit

G93

Coordinate system setting

G94

Feed rate in $ipm$

G95

Feed rate in $ipr$

G96

Surface cutting speed

G97

Rotational speed $rpm$

G98

withdraw the tool to the starting point or feed per minute

G99

withdraw the tool to a safe plane or feed per revolution

G101

Spline interpolation

M00

program stop

M01

optional stop using stop button

M02

end of program

M03

spindle on CW

M04

spindle on CCW

M05

spindle off

M06

tool change

M07

flood with coolant

M08

mist with coolant or turn on accessory

M09

coolant off or turn off accessory

M10

turn on accessory

M11

turn off accessory or tool change

M17

subroutine end

M20

tailstock back or Chain to next program

M21

tailstock forward

M22

Write current position to data file

M25

open chuck or set output #$1$ off

M26

close chuck or set output #$1$ on

M30

end of tape (rewind)

M35

set output #$2$ off

M36

set output #$2$ on

M38

put stepper motors on low power standby

M47

restart a program continuously, or a fixed number of times

M71

puff blowing on

M72

puff blowing off

M96

compensate for rounded external curves

M97

compensate for sharp external curves

M98

subprogram call

M99

return from subprogram, jump instruction

M101

move x-axis home

M102

move y-axis home

M103

move z-axis home

Annn

an orientation, or second x-axis spline control point

Bnnn

an orientation, or second y-axis spline control point

Cnnn

an orientation, or second z-axis spline control point, or chamfer

Fnnn

a feed value (in $ipm$ or $m/s$, not $ipr$), or thread pitch

Innn

x-axis center for circular interpolation, or first x-axis spline control point

Jnnn

y-axis center for circular interpolation, or first y-axis spline control point

Knnn

z-axis center for circular interpolation, or first z-axis spline control point

Lnnn

arc angle, loop counter and program cycle counter