LinuxCNC "G-Code" Quick Reference

Code	Parameters	Description
Motion	(X Y Z A B C U V W apply to all motions)
G0		Rapid motion
G1		Coordinated motion ("Straight feed")
G2, G3	I J K or R, P	Coordinated helical motion ("Arc feed") CW or CCW
G4	P	Dwell (no motion for P seconds)
G5	I J P Q	Cubic spline
G5.1	I J	Quadratic spline
G5.2	P L	NURBS, add control point
G5.3		NURBS, execute
G38.2…G38.5		Straight probe
G33	K	Spindle-synchronized motion
G33.1	K	Rigid tapping
G80		Cancel motion mode
Canned cycles	(X Y Z or U V W apply to canned cycles, depending on active plane)
G81, G82	R L (P)	Drilling cycle without (with) dwell
G83, G73	R L Q	Peck and Chip-break drilling cycles
G85, G89	R L (P)	Boring cycle without (with) dwell
G76	P Z I J R K Q H L E	Multipass lathe threading cycle
Distance Mode
G90		Absolute distance mode
G91		Incremental distance mode
G90.1		Arc centers I,J,K are absolute
G91.1		Arc centers I,J,K are relative to the arc's starting point
G7		X Diameter mode (lathe)
G8		X Radius mode (lathe)
Feed Rate Mode
G93		Inverse time feed rate
G94		Units per minute feed rate
G95		Units per revolution
Spindle Control
M3, M4	S	Turn spindle clockwise or counterclockwise
M5		Stop spindle
G96	S D	CSS mode (Constant Surface Speed)
G97		RPM mode
Coolant
M7		Turn mist on
M8		Turn flood on
M9		Turn all coolant off
Tool Length Offset
G43	H	Use tool length offset from tool table
G43.1	I K	Use specified tool length offset for transient tool
G49		Cancel tool length offset
Stopping
M0		Program Pause
M1		Optional Pause
M2, M30		End Program
M60		Pallet Change Pause
Units
G20		Inches
G21		Millimeters
Plane Selection	(affects G2, G3, G81…G89, G40…G42)
G17		Select XY plane
G18		Select XZ plane
G19		Select YZ plane
Cutter Radius Compensation
G40		Cancel cutter radius compensation
G41,G42	D	Start cutter radius compensation left or right
G41.1, G42.1	D L	Start cutter radius compensation left or right, transient tool
Path Control Mode
G61		Exact Path mode
G61.1		Exact Stop mode
G64	P	Continuous mode with optional path tolerance
Return Mode in Canned Cycles
G98		Retract to prior position
G99		Retract to R position
Other Modal Codes
F		Set Feed Rate
S		Set Spindle Speed
T		Select Tool (also see M6)
M48, M49		Speed and Feed Override Control
M50	P0 (off) or P1 (on)	Feed Override Control
M51	P0 (off) or P1 (on)	Spindle Speed Override Control
M52	P0 (off) or P1 (on)	Adaptive Feed Control
M53	P0 (off) or P1 (on)	Feed Stop Control
G54…G59.3		Select coordinate system
Flow-control Codes
O- sub		Subroutines, sub/endsub call
O- while		Looping, while/endwhile do/while
O- if		Conditional, if/else/endif
O- repeat		Run enclosed code more than once
Input/Output Codes
M62…M65	P	Digital Output Control
M66	P E L Q	Digital and Analog Input Control
M67	T	Analog Output Synchronized with Motion
M68	T	Analog Output Immediate
Non-modal Codes
M6	T	Change tool
M61	Q	Set Current Tool
G4	P	Dwell (seconds)
G10 L1	P Q R axes	Tool offset, radius, orientation setting
G10 L10	P axes	Tool offset, setting calculated from workpiece
G10 L11	P axes	Tool offset, setting calculated from fixture
G10 L2	P R axes	Coordinate system origin, rotation setting
G10 L20	P axes	Coordinate system origin setting calculated
G28, G28.1		Return to or Set reference point 1
G30, G30.1		Return to or Set reference point 2
G53		Motion in machine coordinate system
G92	axes	Offset coordinate systems and set parameters
G92.1		Cancel offset coordinate systems and set parameters to zero
G92.2		Cancel offset coordinate systems but do not reset parameters
G92.3		Apply parameters to offset coordinate systems
M101…M199	P Q	User-defined M-codes
Comments & Messages
(…)		An inline comment
(MSG,…)		Display a message "…" to the user (e.g., in a popup)
(DEBUG,…)		Display a message (with variables substituted) like MSG
(PRINT,…)		Display a message (with variables substituted) to stderr