Haas Lathe · G-code
G50 Spindle Speed Limit
Clamps the maximum spindle RPM. Always program it before G96 constant surface speed.
What G50 does on a Haas lathe
G50 S sets the highest RPM the spindle is allowed to reach. In G96 constant surface speed, RPM climbs as the tool moves towards the centreline, so without a clamp it would run up to the machine's maximum.
Pick the clamp from the chuck, jaws, workholding and part — not from the machine's maximum speed.
G50 format
| Address | Meaning |
|---|---|
S | Maximum spindle RPM |
G50 example program
G50 S2500 (never exceed 2500 RPM)
G96 S600 M03 (600 SFM)⚠ Watch out
Facing to centre in G96 without a G50 clamp sends the spindle to full speed. With heavy soft jaws or an unbalanced part, that is dangerous.
Related codes
G50 questions
Why use G50 before G96?
G96 increases RPM as diameter shrinks. G50 caps it so it never goes faster than your setup allows.
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.