CNC Machinist Calculator UltraHome › G-codes › Siemens 840D 828D › G2
G2 Circular interpolation clockwise
Siemens 840D 828D G-code · Mill and lathe
Cuts a clockwise arc in the active plane. The arc is set by end point and center (I J K), end point and radius (CR=), or with an opening angle (AR=). A full circle needs the center form.
Format
G2 X Y I J F or G2 X Y CR= F or G2 X Y AR= F or G2 I J AR= F
Addresses
| Address | What it does |
|---|---|
X Y Z | Arc end point |
I J K | Arc center, incremental from the start point by default. I=AC() gives an absolute center. |
CR= | Arc radius. Negative value for an arc greater than 180 degrees. |
AR= | Opening angle of the arc in degrees |
F | Feed rate |
How it works
Modal, G group 1 (motion).
Example program
G17 G90 G54 ; XY PLANE, ABSOLUTE
G0 X20 Y0 Z2 ; START POINT
G1 Z-2 F100 ; FEED TO DEPTH
G2 X0 Y-20 CR=20 F300 ; QUARTER ARC BY RADIUS
…
G0 X20 Y0 Z2 ; START POINT
G1 Z-2 F100 ; FEED TO DEPTH
G2 X0 Y-20 CR=20 F300 ; QUARTER ARC BY RADIUS
…
The full 6-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- Direction is seen looking from the plus side of the tool axis onto the active plane, so check G17, G18 or G19 first.
- CR= cannot make a full circle. Use I J K for a 360 degree move.
- I J K are incremental from the arc start point unless written as I=AC() or the machine data says otherwise.
Related codes
G3 · CIP · G17 · G18 · G19 · AC
G2 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Fanuc | Circular interpolation clockwise |
| Haas NGC | Circular interpolation clockwise |
| Mazak (EIA) | Circular interpolation, clockwise |
| Okuma OSP | Circular interpolation clockwise |
| Mitsubishi M70 M80 | Circular move clockwise |
| Brother Speedio | Circular interpolation clockwise |
| Heidenhain TNC (ISO) | Clockwise arc, Cartesian |
| Fagor 8055 8065 | Clockwise circular interpolation |
| LinuxCNC Tormach | Clockwise arc or helix |
| Mach3 Mach4 | Clockwise arc |
| Centroid CNC12 Acorn | Clockwise arc or helix |
| Hurco WinMax (NC) | Circular or helical move clockwise |
| Fadal | Circular interpolation clockwise |
| Swiss (Citizen Star) | Circular move clockwise |
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 G2 in the app All Siemens 840D 828D G-codes