BSPT (R) - British tapered pipe
1/8-28 BSPT pipe thread: 28 TPI, major Ø 9.728 mm.
Profile
| Designation | 1/8-28 BSPT |
|---|---|
| Major (outside) diameter | 9.728 mm · 0.383" |
| Pitch | 0.907 mm · 28 TPI |
| Pitch diameter | 9.139 mm · 0.3598" |
| Minor diameter (external) | 8.615 mm · 0.3392" |
| Minor diameter (internal) | 8.746 mm · 0.3443" |
| Recommended tap drill | 8.4 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.
1/8-28 BSPT is a BSPT pipe thread running at 28 threads per inch on a 9.728 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 8.4 mm before tapping 1/8-28 BSPT. BSPT (R) is a 55° Whitworth tapered thread that seals on the flanks.
1/8-28 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.
1/8-28 BSPT runs at 28 threads per inch, a pitch of 0.907 mm, on a major diameter of 9.728 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 1/8 pipe is 0.405 in across the outside whatever the schedule; at standard wall (std) the wall is 0.068 in and the bore 0.269 in.
Full dimensions for the standard wall · every schedule in the chart
Nearby sizes