CNC Machinist Calculator UltraHome › G-codes › Okuma OSP › G74
G74 Reverse tapping cycle / Transverse grooving and drilling cycle
Okuma OSP G-code · Mill, Lathe
On mills: Reverse tapping cycle
Taps a left hand thread. The spindle runs reverse going in and forward coming out.
Verify on your machine. This entry could not be fully checked against the maker manual. Check your machine manual before you run it.
Format
Addresses
| Address | What it does |
|---|---|
X Y | Hole position |
Z | Thread depth |
R | R point |
F | Feed, spindle speed times pitch |
How it works
Modal, fixed cycle group. Cancel with G80.
Example program
N1 G15 H1 (WORK COORDINATE SYSTEM 1)
N2 T7 M06 (.500-13 LH TAP)
N3 G00 G90 X1. Y1. S300 M04 (REVERSE SPINDLE)
…
The full 7-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- Start the spindle in reverse with M04 before the cycle.
- Feed must equal RPM times pitch or the tap breaks.
On lathes: Transverse grooving and drilling cycle
Pecks along Z. Used for face grooves and peck drilling on center with a turret drill.
Format
Addresses
| Address | What it does |
|---|---|
X Z | Target point |
I | Shift in X, diameter |
K | Shift in Z |
D | Depth of cut per peck |
DA | Retract amount |
L | Total infeed before a full withdrawal |
F | Feed rate |
E | Dwell at the Z target |
T | Tool offset used at the target point |
How it works
Compound fixed cycle. One shot.
Example program
N1 G50 S3000 (MAX SPINDLE 3000 RPM)
N2 G00 X0 Z.2 T090909 (.500 DRILL)
N3 G97 S1200 M03 (1200 RPM)
…
The full 6-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- For a drill on center use X0 and no I shift.
- If DA is left out the retract comes from a parameter.
Related codes
G74 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Fanuc | Left hand tapping cycle |
| Haas NGC | Reverse tapping cycle |
| Mazak (EIA) | Reverse tapping cycle |
| Mitsubishi M70 M80 | Reverse tapping cycle |
| Brother Speedio | Left hand tapping cycle |
| Siemens 840D 828D | Reference point approach |
| Fagor 8055 8065 | Home search |
| LinuxCNC Tormach | Left hand tapping cycle |
| Mach3 Mach4 | Left hand tapping, Mach4 |
| Centroid CNC12 Acorn | Left hand tapping cycle |
| Hurco WinMax (NC) | Left hand tap (ISNC) or single quadrant arc (BNC) |
| Fadal | Left hand tap |
| Swiss (Citizen Star) | Face peck drilling and grooving cycle |
Every G-code for Okuma OSP in your pocket. The app has the full example programs, search by number or shop word, a line decoder and calculators for tapping, threading and drilling.
Open G74 in the app All Okuma OSP G-codes