Haas Lathe · G-code
G71 OD/ID Stock Removal Cycle
Roughs a turned profile in Z-direction passes, leaving finish stock for G70. Works for OD and ID.
What G71 does on a Haas lathe
G71 reads the finished profile between blocks P and Q and removes material in passes along Z, each D deep (radius). It leaves U (X, on diameter) and W (Z) stock for the finishing pass.
Haas uses a single-line format. U is positive for OD turning and negative for ID boring, which tells the control which side of the profile to leave stock on.
G71 format
| Address | Meaning |
|---|---|
P | First block of profile |
Q | Last block of profile |
U | X finish allowance on diameter (+ OD, − ID) |
W | Z finish allowance |
D | Depth of cut per pass (radius) |
F | Roughing feed |
R1 | Optional Type II (allows pockets) |
G71 example program
G00 X2.1 Z0.1
G71 P1 Q2 U0.02 W0.005 D0.08 F0.012
N1 G00 X0.75
G01 Z0. F0.006
X1. Z-0.125
Z-1.
X1.5
N2 X2.1
G70 P1 Q2⚠ Watch out
The tool must start outside the stock (above the largest OD on an OD cycle). Starting inside the material makes the first pass a full-width crash. And a negative U on an OD profile leaves the finish stock on the wrong side.
Related codes
G71 questions
What is D in a Haas G71 cycle?
The depth of each roughing pass, per side (radius).
Why is U negative for boring?
A negative U leaves finish stock on the inside diameter, which is correct when boring.
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.