Specifications of International Thread Standards

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
TPIPitch
mm
R 1/16"Rp 1/16"37.7236.561280.907
R 1/8"Rp 1/8"69.7288.566280.907
R 1/4"Rp 1/4"813.15711.445191.337
R 3/8"Rp 3/8"1016.66214.950191.337
R 1/2"Rp 1/2"1520.95518.631141.814
R 3/4"Rp 3/4"2026.44124.117141.814
R 1"Rp 1"2533.24930.291112.309
R 1 1/4"Rp 1 1/4"3241.91038.952112.309
R 1 1/2"Rp 1 1/2"4047.80344.845112.309
R 2"Rp 2"5059.61456.656112.309
R 2 1/2"Rp 2 1/2"6575.18472.226112.309
R 3"Rp 3"8087.88484.926112.309
R 4"Rp 4"100113.030110.072112.309
R 5"Rp 5"125138.430135.472112.309
R 6"Rp 6"150163.830160.872112.309
Tapered Whitworth Pipe Thread