# LinuxCNC G43.1 Dynamic Tool Length Offset

Instructions · `G43.1` · verification: source checked

G43.1 is a LinuxCNC G-code that dynamically replaces the current tool length offset values for the specified axes. It does not cause motion; the next move of a compensated axis uses the new offset. The change is not written to the tool table.

## Specification

| Property | Value |
|---|---|
| Language | gcode |
| Code | G43.1 |
| Syntax | G43.1 axes |
| Dialect | LinuxCNC |

### Parameters

| Name | Description |
|---|---|
| axes | Axes whose current offset(s) are replaced. |

## Safety

- Programming motion on the same line as G43.1 is an error.

## Study notes

- G43.1 does not cause any motion; it changes subsequent motions by replacing the current offset(s) of axes.
- The next time a compensated axis is moved, that axis’s endpoint is the compensated location.
- G43.1 does not write to the tool table.
- Example: after T1 M6 G43 leaves the DRO showing Z1.500, G43.1 Z0.250 replaces the current tool offset with 0.250 and the DRO shows Z0.250.
- The documented prototype is G43.1 axes.
- The section cross-references G90, T, M6 and G43; no matching reference ids are available.

## Sources

1. [G-Codes](https://linuxcnc.org/docs/html/gcode/g-code.html#gcode:g43.1) (accessed 2026-10-26)

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Source page: https://machineschema.com/instruction/gcode-g43-1  
JSON: https://machineschema.com/instruction/gcode-g43-1.json  
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite Machine Schema and the original sources.