G1-1/4 thread: 41.91 mm × 11 TPI
Threads › G1-1/4
G1-1/4 is a BSP parallel (G) thread: 41.91 mm major diameter, 11 TPI (2.309 mm pitch), 55° form. Tap drill 39.5 mm.
| Standard | BSP parallel (G) |
|---|---|
| Major diameter | 41.91 mm (1.65″) |
| Pitch | 11 TPI (2.309 mm) |
| Thread angle | 55° |
| Minor diameter, bolt | 38.95 mm |
| Minor diameter, nut | 38.95 mm |
| Tap drill | 39.5 mm |
| Usual class | A bolt |
Minor diameters worked out from the basic profile: major Ø − 1.28065 × pitch.
Open G1-1/4 in BenchsmithAdd to order list
Measure it
Bolt: Measure across the crests of the bolt with the caliper jaws. Worn bolts read 0.1 to 0.3 under.
Nut or tapped hole: Measure across the tops of the threads inside the nut or hole with the inside jaws. That is the minor Ø. Worn or oversize holes read a little over.
Close in size, won't mate
- R1-1/4Ø41.91 mm, 11 TPI
- M42Ø42 mm, 4.5 mm pitch
- M42×3Ø42 mm, 3 mm pitch
- M42×2Ø42 mm, 2 mm pitch
- 1-1/4-11.5 NPTØ42.16 mm, 11.5 TPI
One size up or down
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.