# LinuxCNC G93

Instructions · `G93` · verification: source checked

G93 selects inverse time feed rate mode in LinuxCNC. In this mode an F word sets the duration of a move: the move is completed in one divided by the F number minutes, so F2.0 finishes the move in half a minute. It does not affect G0 rapid moves; G94 (units per minute) and G95 (units per revolution) are the other feed rate modes.

## Specification

| Property | Value |
|---|---|
| Language | gcode |
| Code | G93 |
| Group | Feed Rate Mode |
| Dialect | LinuxCNC |

### Parameters

| Name | Description |
|---|---|
| F | Inverse time value: the move is completed in 1 divided by the F number minutes (F2.0 means half a minute). |

## Connected

- Related: [LinuxCNC F: Set Feed Rate](https://machineschema.com/instruction/word-f.md), [LinuxCNC S (Set Spindle Speed)](https://machineschema.com/instruction/word-s.md), [LinuxCNC G02](https://machineschema.com/instruction/gcode-g02.md), [LinuxCNC G1 Linear Move](https://machineschema.com/instruction/gcode-g01.md)

## Study notes

- Inverse time mode requires an F word on every line that has a G1, G2 or G3 motion, whether explicit or implicit.
- An F word on a line without G1, G2 or G3 is ignored while inverse time mode is active.
- Inverse time feed rate mode does not affect G0 rapid moves.
- It is an error if inverse time feed mode is active and a line with G1, G2 or G3 does not have an F word.
- It is an error if a new feed rate is not specified after switching to G94 or G95.
- G93 belongs to the feed rate mode group with G94 (units per minute) and G95 (units per revolution).

## Sources

1. [G-Codes](https://linuxcnc.org/docs/html/gcode/g-code.html#gcode:g93-g94-g95) (accessed 2026-10-26)

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Source page: https://machineschema.com/instruction/gcode-g93  
JSON: https://machineschema.com/instruction/gcode-g93.json  
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite Machine Schema and the original sources.