G1 thread: 33.25 mm × 11 TPI
Threads › G1
G1 is a BSP parallel (G) thread: 33.25 mm major diameter, 11 TPI (2.309 mm pitch), 55° form. Tap drill 30.75 mm.
| Standard | BSP parallel (G) |
|---|---|
| Major diameter | 33.249 mm (1.309″) |
| Pitch | 11 TPI (2.309 mm) |
| Thread angle | 55° |
| Minor diameter, bolt | 30.29 mm |
| Minor diameter, nut | 30.29 mm |
| Tap drill | 30.75 mm |
| Usual class | A bolt |
Minor diameters worked out from the basic profile: major Ø − 1.28065 × pitch.
Open G1 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
- R1Ø33.25 mm, 11 TPI
- 1-11.5 NPTØ33.4 mm, 11.5 TPI
- M33Ø33 mm, 3.5 mm pitch
- M33×2Ø33 mm, 2 mm pitch
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.