Whitworth Pipe Thread for pipes and fittings. Parallel female thread and tapered male thread (taper 1 : 16).
TPI – Pitch – Tap Maj./Min. Diameter
Male Thread Dia.
Pitch mm
TPI
Tap/Drill mm
R 1/16”
6.561
28
0.907
R 1/8”
8.566
28
0.907
R 1/4”
11.445
19
1.337
R 3/8”
14.95
19
1.337
R 1/2”
18.631
14
1.814
R 3/4”
24.117
14
1.814
R 1”
30.291
11
2.309
R 1 1/4”
38.952
11
2.309
R 1 1/2”
44.845
11
2.309
R 2”
56.656
11
2.309
R 2 1/2”
72.226
11
2.309
R 3”
84.926
11
2.309
R 4”
110.072
11
2.309
R 5”
135.472
11
2.309
R 6”
160.872
11
2.309
Male Thread Dia.
Female Thread Dia.
Maj. Dia. mm
Min. Dia. mm
R 1/16”
Rp 1/16”
3
7.723
R 1/8”
Rp 1/8”
6
9.728
R 1/4”
Rp 1/4”
8
13.157
R 3/8”
Rp 3/8”
10
16.662
R 1/2”
Rp 1/2”
15
20.955
R 3/4”
Rp 3/4”
20
26.441
R 1”
Rp 1”
25
33.249
R 1 1/4”
Rp 1 1/4”
32
41.91
R 1 1/2”
Rp 1 1/2”
40
47.803
R 2”
Rp 2”
50
59.614
R 2 1/2”
Rp 2 1/2”
65
75.184
R 3”
Rp 3”
80
87.884
R 4”
Rp 4”
100
113.03
R 5”
Rp 5”
125
138.43
R 6”
Rp 6”
150
163.83
