1-1/4-11.5 NPT thread: 42.16 mm × 11.5 TPI
Threads › 1-1/4-11.5 NPT
1-1/4-11.5 NPT is an NPT taper thread: 42.16 mm pipe OD, 11.5 TPI (2.209 mm pitch), 60° form. Tap drill 38.1 mm. Taper thread: the Ø changes along the length, measure near the start.
| Standard | NPT taper |
|---|---|
| Pipe OD | 42.164 mm (1.66″) |
| Pitch | 11.5 TPI (2.209 mm) |
| Thread angle | 60° |
| Tap drill | 38.1 mm |
Open 1-1/4-11.5 NPT 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
- M42Ø42 mm, 4.5 mm pitch
- M42×3Ø42 mm, 3 mm pitch
- M42×2Ø42 mm, 2 mm pitch
- G1-1/4Ø41.91 mm, 11 TPI
- R1-1/4Ø41.91 mm, 11 TPI
One size up or down
- 1-11.5 NPTØ33.4 mm (down)
- 1-1/2-11.5 NPTØ48.26 mm (up)
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.