LinuxCNC G84 Right-hand Tapping Cycle, Dwell

G84 is a canned cycle for right-hand tapping with a floating chuck and a dwell at the bottom of the hole. The cycle feeds the Z axis to the programmed depth, stops the selected spindle, starts counterclockwise spindle rotation, dwells for the P time, then feeds back to clear Z. It does not use synchronized motion.

Source checked13/13 values · 2026-10-26

Specification

1 source

Language	gcode
Code	G84
Group	canned cycles
Syntax	G84 (X- Y- Z-) or (U- V- W-) R- L- P- $- F-
Dialect	LinuxCNC

Parameters

Name	Description
R	Retract position along the Z axis.
L	Used in incremental mode; number of times to repeat the cycle. See G81 for examples.
P	Dwell time in seconds.
$	Selected spindle.
F	Feed rate (spindle speed multiplied by distance traveled per revolution (thread pitch)).

Study notes

The G84 cycle is intended for tapping with a floating chuck and dwell at the bottom of the hole.
G84 does not use synchronized motion.
The dwell length is specified by the P word in the G84 block.
The feed rate F is spindle speed multiplied by distance per revolution (thread pitch); for example S100 with 1.25 mm per revolution gives F125.
The cycle disables feed and speed overrides, then restores them to their previous state after the retract move.
The L word is used in incremental mode as the number of times to repeat the cycle.
Canned cycles are performed with respect to the currently selected plane; rotary axis words are not allowed in canned cycles.
Canned cycle axis words are X, Y, Z or U, V, W depending on the selected plane.

Safety

G84 does not use synchronized motion.
Feed and speed overrides are disabled during the G84 cycle and restored afterward.