CNC Machinist Calculator UltraG33 Thread cutting, constant lead
Fanuc G-code · Mill
Cuts a straight thread by syncing Z feed to the spindle encoder. On a mill it is rare and mostly used with single point boring bar threading.
Verify on your machine. This entry could not be fully checked against the maker manual. Check your machine manual before you run it.
Format
G33 Z F
Addresses
| Address | What it does |
|---|---|
Z | End point of the thread |
F | Lead of the thread, inches per revolution |
How it works
Modal, group 01.
Example program
G90 G54 G00 X0. Y0. S300 M03 (CENTER OF BORE)
G43 H07 Z.2 (START ABOVE PART)
G33 Z-.75 F.0625 (16 TPI LEAD)
M19 (ORIENT SPINDLE IF BUILDER SUPPORTS)
…
G43 H07 Z.2 (START ABOVE PART)
G33 Z-.75 F.0625 (16 TPI LEAD)
M19 (ORIENT SPINDLE IF BUILDER SUPPORTS)
…
The full 5-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- This is an option on machining centers. Thread milling with G02 or G03 helix is far more common.
- Spindle speed override and feed hold should not be used during G33.
- Every pass must start from the same spindle angle and Z point to stay in the same groove.
Related codes
G33 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Okuma OSP | Fixed thread cycle, longitudinal |
| Siemens 840D 828D | Thread cutting with constant lead |
| Fagor 8055 8065 | Electronic threading |
| LinuxCNC Tormach | Spindle synchronized motion |
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