Female BSPP Fixed Brass Hosetail. 

Check your pipe threads before you order!

In Great Britain BSP British Standard Pipe threads are commonly used. These are either parallel (BSPP) which normally seal on a washer or 'O' ring seal, or tapered (BSPT) which taper along their length and normally seal by two mating threads and/ or tape.

How to measure your thread:

Use a tape rule or (vernier gauge) to measure across the outside of the male thread. Note that a thread that measures 0.5" is not 1/2" BSP thread!

Using the table below we can see that 0.5" is actually 1/4" BSP thread. Similarly, a thread that measures 1.0" is actually 3/4" BSP thread.


BSP Size Max. diameter min. diameter Thread pitch
  mm inch mm inch (mm)        TPI
1/16" 7.723 0.304 6.561 0.258 28
1/8" 9.728 0.383 8.565 0.337 28
1/4" 13.157 0.518 11.445 0.451 19
3/8" 16.662 0.656 14.95 0.589 19
1/2" 20.955 0.825 18.633 0.734 14
5/8" 22.911 0.902 20.589 0.811 14
3/4" 26.441 1.041 24.12 0.95 14
1" 33.249 1.309 30.292 1.193 11
1 1/4" 41.91 1.65 38.953 1.534 11
1 1/2" 47.803 1.882 44.846 1.766 11
2" 59.614 2.347 56.657 2.231 11
2 1/2" 75.184 2.96 72.227 2.844 11
3" 87.884 3.46 84.927 3.344 11
4" 113.03 4.45 110.073 4.334 11
5" 138.43 5.45 135.472 5.334 11
6" 163.83 6.45 160.872 6.334 11