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G41 Tool radius compensation left

Siemens 840D 828D G-code · Mill and lathe

Offsets the tool path to the left of the contour, seen in the cutting direction, by the radius in the active D number. With a right hand cutter in M3 this is climb milling.

Format

G41 G1 X Y F

Addresses

Address	What it does
`X Y`	Approach move in the working plane
`D`	Offset number holding the radius, normally set together with T

How it works

Modal, G group 7 (radius compensation). Cancel with G40.

Example program

T2 D1 ; END MILL, OFFSET D1
M6
S3000 M3
G0 X-10 Y-10 Z2
…

The full 9-line example is in the app. Example is in inch. Check offsets and clearances first.

Watch out for

Start compensation on a G0 or G1 move in the working plane. G2 or G3 cannot start it.
Siemens has no H word. Length and radius both come from the T and D numbers.
Lathe nose radius compensation also needs the cutting edge position stored in the D data.

Related codes

G40 · G42 · G17

G41 on other controls

The same number can mean something different on another control.

Control	Meaning
Fanuc	Cutter compensation left
Haas NGC	Cutter compensation left
Mazak (EIA)	Cutter radius compensation left
Okuma OSP	Cutter radius compensation left
Mitsubishi M70 M80	Cutter radius comp left
Brother Speedio	Cutter compensation left
Heidenhain TNC (ISO)	Radius compensation left
Fagor 8055 8065	Tool radius compensation left
LinuxCNC Tormach	Cutter compensation left
Mach3 Mach4	Cutter comp left
Centroid CNC12 Acorn	Cutter compensation left
Hurco WinMax (NC)	Cutter compensation left
Fadal	Cutter radius compensation left, climb
Swiss (Citizen Star)	Nose radius compensation left

Every G-code for Siemens 840D 828D in your pocket. The app has the full example programs, search by number or shop word, a line decoder and calculators for tapping, threading and drilling.

Open G41 in the app All Siemens 840D 828D G-codes

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