Haas Lathe · G-code
G99 Feed per Revolution
F is inches (or mm) per spindle revolution. The normal feed mode on a lathe.
What G99 does on a Haas lathe
In G99 the feed is tied to spindle rotation: F0.008 moves the tool 0.008 for every revolution, regardless of RPM. That keeps chip load constant as G96 changes speed.
G98 switches to feed per minute, used mainly with live tooling. On a mill, G98/G99 are canned cycle return levels — a completely different meaning.
G99 format
| Address | Meaning |
|---|---|
G99 | Feed per revolution |
G98 | Feed per minute |
G99 example program
G99 G01 Z-1. F0.008⚠ Watch out
Copying a mill-style feed like F20. into a lathe program in G99 means 20 inches per revolution. The machine will try.
Related codes
G99 questions
Is G99 feed per rev on a Haas lathe?
Yes. G99 is feed per revolution and G98 is feed per minute on a Haas lathe.
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.