CNC Machinist Calculator UltraG74 Left hand tap
Fadal G-code · Mill
Taps a left hand thread with a floating holder. The spindle runs CCW in, then reverses 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
G74 X Y Z R0 F
Addresses
| Address | What it does |
|---|---|
Z | Tap depth |
R0 | R0 plane where feed starts. Must be at or below the start plane |
F | Format 2 feed, lead times RPM |
How it works
Modal fixed cycle. Cancel with G80.
Example program
N1 G0 G40 G49 G80 G90 G17 (FORMAT 2 SAFE START)
N2 T6 M6 (.250-20 LH TAP)
N3 G0 G90 G54 X1. Y1. S400 M4 (CCW FOR LH TAP)
N4 G43 H6 Z1. M8
…
N2 T6 M6 (.250-20 LH TAP)
N3 G0 G90 G54 X1. Y1. S400 M4 (CCW FOR LH TAP)
N4 G43 H6 Z1. M8
…
The full 7-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- Start the spindle with M4.
- In Format 2 F is lead times RPM. Format 1 used Q for the thread lead and F for RPM.
- For rigid tapping use G74.2 then G74.1.
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 |
| Okuma OSP | 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) |
| Swiss (Citizen Star) | Face peck drilling and grooving cycle |
Every G-code for Fadal 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 Fadal G-codes