BSPpipe55° flankISO 228-1

2-11 BSP Thread Dimensions

2-11 BSP is a pipe British Standard Pipe (parallel) thread. There are 11 threads per inch on a 2.3469 in major diameter, giving a metric-equivalent pitch of 2.309 mm. The size label is a nominal bore rather than a diameter.

Major Ø2.3469 in
Threads per inch11
Pitch (metric)2.309 mm
Pitch Ø2.289 in
Tap drill2.2559 in

Thread profile

millimetres unless stated
Thread profile — 2-11 BSPd 59.61d2 58.14d3 56.66mm55°P 2.309h3 1.479tap ⌀57.3
2-11 BSP — basic profile55° flank angle · Not to scale

Basic information

Designation
2-11 BSP
Thread system
British Standard Pipe (parallel)
Series
pipe
Standard
ISO 228-1
Basic profile
Whitworth basic profile
Flank angle
55°

Dimensions

Major diameter
2.3469 in / 59.61 mm
Pitch (metric equivalent)
2.309 mm
Threads per inch
11
Pitch diameter
2.289 in / 58.14 mm
Minor diameter (external)
2.2307 in / 56.66 mm
Minor diameter (internal)
2.2307 in / 56.66 mm
Thread depth
0.0582 in / 1.479 mm
Recommended tap drill
Ø 2.2559 in / 57.3 mm

How these values are derived

tabulated standard values

This is a pipe thread, so the published dimensions are tabulated values from ISO 228-1 rather than figures derived from a formula: a pipe size is a nominal bore, and the relationship between that bore and the thread diameter is historical, not geometric. Diameters are quoted at the gauge plane; the thread itself is tapered, so the actual size changes along its length.

Compatible parts0 specification pages

No specification in this database uses 2-11 BSP. That is expected: the catalogue covers machine screws, bolts, nuts and washers, and pipe threads belong to fittings, which are a separate family of parts. The dimensions above are still the standard ones for the thread itself.

Related

Neighbouring sizes in British Standard Pipe (parallel).

7/8-14 BSP1-11 BSP1-1/4-11 BSP1-1/2-11 BSP