BSPP (G) / BSPT (R)

| British Standard Pipe Taper thread (R)

British Standard Pipe Taper (BSPT) threads are characterized by their tapered design, denoted by the letter R. The diameter of BSPT threads gradually increases or decreases along the length of the thread. The taper ratio is 1:16, meaning that for every 16 units of measurement increase in distance from the end, the diameter of the thread increases by 1 unit of measurement. This tapering feature allows for a secure fit and effective sealing when joining BSPT threaded components, ensuring reliable connections in various applications.

The thread profile adheres to the British Standard Whitworth standard:

  1. Symmetrical V-thread in which the angle between the flanks is 55° (measured in an axial plane)
  2. One-sixth of this sharp V is truncated at the top and the bottom
  3. The threads are rounded equally at crests and roots by circular arcs ending tangentially with the flanks where r ≈ 0.1373P
  4. The theoretical depth of the thread is therefore 0.6403 times the nominal pitch h ≈ 0.6403P

| British Standard Pipe thread (G)

British Standard Pipe Parallel (BSPP) threads, also known as British Standard Pipe Fitting (BSPF) threads and British Standard Pipe Mechanical (BSPM) threads, maintain a consistent diameter along their length. These threads are designated by the letter G. Unlike tapered threads, BSPP threads do not have a taper and instead feature a parallel profile throughout. This design allows for easy assembly and disassembly of components, making BSPP threads suitable for various applications that require a secure and reliable connection.

The thread profile conforms to the British Standard Whitworth standard:

  1. Symmetrical V-thread in which the angle between the flanks is 55° (measured in an axial plane)
  2. One-sixth of this sharp V is truncated at the top and the bottom
  3. The threads are rounded equally at crests and roots by circular arcs ending tangentially with the flanks where r ≈ 0.1373P
  4. The theoretical depth of the thread is therefore 0.6403 times the nominal pitch h ≈ 0.6403P