Haas Mill · G-code
G41 Cutter Compensation Left
Offsets the tool to the left of the programmed path by the radius in the D register. Climb milling with a right-hand tool.
What G41 does on a Haas mill
G41 shifts the tool centre to the left of the programmed path (looking in the direction of travel) by the amount stored in the D offset. That lets you program the part print dimensions and adjust size at the machine through diameter wear.
Comp must be turned on during a linear G01 move — the lead-in — and off with G40 on a linear lead-out. G42 is the same to the right, which gives conventional milling with a right-hand cutter.
G41 format
| Address | Meaning |
|---|---|
D | Diameter/radius offset number |
G40 | Cancel |
X Y | Lead-in end point (must be a linear move) |
G41 example program
G00 X-0.75 Y-0.75
Z-0.25
G41 G01 X0. Y-0.5 D01 F20. (lead-in, comp on)
Y2.
X3.
G40 G01 X3.75 Y2.75 (lead-out, comp off)⚠ Watch out
The lead-in move must be at least as long as the tool radius, and you cannot turn comp on during an arc. Inside corners smaller than the tool radius will alarm or gouge.
Related codes
G41 questions
Is G41 climb or conventional milling?
With a standard right-hand cutter and the spindle in M03, G41 gives climb milling.
Where does the D offset value come from?
From the tool offset page. Enter the tool diameter (or radius, depending on settings) and adjust size through the wear column.
Independent reference. Not affiliated with, sponsored by or endorsed by Haas Automation, Inc. Haas is a trademark of its respective owner. Always confirm codes against your machine's operator manual — options and settings vary by model and software version.