Specifications of International Thread Standards

Whitworth Tapered Pipe Thread

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.
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 20,995 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" R 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
Tapered Whitworth Pipe Thread
Nut Washer
Screw Nut