Siemens SINUMERIK 840Di sl Programming Manual page 170

Motion commands
4.15 Thread cutting with constant lead (G33)
Start point offset SF - production of multi-turn threads
Threads with offset cuts are programmed by specifying starting point offsets in the G33
block.
The start point offset is specified as an absolute angle position at address SF=. The
associated setting data is changed accordingly.
Example: SF=45
Meaning: Start offset 45°
Value range: 0.0000 to 359.999 degrees
170
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals