Whitworth Tapered Pipe Thread DIN EN 10226-1, DIN EN 10226-2 formerly known as DIN 2999
BSPT (British Standard Tapered Pipe)

Whitworth Pipe Thread for pipes and fittings. Parallel female thread and tapered male thread (taper 1 : 16).
An appropriate sealing compound can be used in the thread to ensure a leak-proof joint.
The flank angle is 55°.

Male Thread
Diameter
Female Thread
Diameter
Pipe Minor
Diameter
mm
Pipe Major
Diameter
mm
Tapping
Drill Size
mm
TPI Pitch
mm
R 1/16" Rp 1/16" 3 7.723 6.561 28 0.907
R 1/8" Rp 1/8" 6 9.728 8.566 28 0.907
R 1/4" Rp 1/4" 8 13.157 11.445 19 1.337
R 3/8" Rp 3/8" 10 16.662 14.950 19 1.337
R 1/2" Rp 1/2" 15 20.955 18.631 14 1.814
R 3/4" Rp 3/4" 20 26.441 24.117 14 1.814
R 1" Rp 1" 25 33.249 30.291 11 2.309
R 1 1/4" Rp 1 1/4" 32 41.910 38.952 11 2.309
R 1 1/2" Rp 1 1/2" 40 47.803 44.845 11 2.309
R 2" Rp 2" 50 59.614 56.656 11 2.309
R 2 1/2" Rp 2 1/2" 65 75.184 72.226 11 2.309
R 3" Rp 3" 80 87.884 84.926 11 2.309
R 4" Rp 4" 100 113.030 110.072 11 2.309
R 5" Rp 5" 125 138.430 135.472 11 2.309
R 6" Rp 6" 150 163.830 160.872 11 2.309