BSPT (R) - British tapered pipe
1-1/4-11 BSPT pipe thread: 11 TPI, major Ø 41.91 mm.
Profile
| Designation | 1-1/4-11 BSPT |
|---|---|
| Major (outside) diameter | 41.91 mm · 1.65" |
| Pitch | 2.309 mm · 11 TPI |
| Pitch diameter | 40.41 mm · 1.591" |
| Minor diameter (external) | 39.077 mm · 1.5385" |
| Minor diameter (internal) | 39.41 mm · 1.5516" |
| Recommended tap drill | 38.75 mm |
Pipe threads are made up to a seal against the mating flanks, not tightened to a bolt preload, so no proof load or tightening-torque figure applies.
The bolt schedule collects the fasteners for one job onto a single sheet - tap drill, wrench size, grade and tightening torque on every line, taken straight from pages like this one. Free schedules hold 3 lines and are saved in this browser only.
1-1/4-11 BSPT is a BSPT pipe thread running at 11 threads per inch on a 41.91 mm major diameter. BSPT (R) is a 55° Whitworth tapered thread that seals on the flanks.
All values are generated from the standard thread formulas (ISO 68-1 / ASME B1.1) and published standard tables - not hand-entered. See the full reference.
Drill 38.75 mm before tapping 1-1/4-11 BSPT. BSPT (R) is a 55° Whitworth tapered thread that seals on the flanks.
1-1/4-11 BSPT is tapered. BSPT (R) is a 55° Whitworth tapered thread that seals as the flanks wedge together, normally with thread sealant or PTFE tape.
1-1/4-11 BSPT runs at 11 threads per inch, a pitch of 2.309 mm, on a major diameter of 41.91 mm.
No. Pipe threads are made up to a seal against the mating flanks, not tightened to a bolt preload, so no proof load or tightening-torque figure applies.
Same diameter
The pipe this thread runs on
NPS 1-1/4 pipe is 1.66 in across the outside whatever the schedule; at standard wall (std) the wall is 0.14 in and the bore 1.38 in.
Full dimensions for the standard wall · every schedule in the chart
Nearby sizes