BSP Thread Specifications
British Standard Pipe Thread - Parallel (BSPP/BSPF)
 
 
 
Inner
 
 
 
 
 
 
Outer
Diameter
 
Threads
Pitch
Thread
Nominal
Dash
Diameter
Male Thread
Pitch
per
Diameter
Height
Size
Size
(mm)
(mm)
(mm)
inch
(mm)
(mm)
               
1/8"
02
9.728
8.566
0.907
28
9.147
0.581
1/4"
04
13.157
11.445
1.337
19
12.301
0.856
3/8"
06
16.662
14.95
1.337
19
15.806
0.856
1/2"
08
20.955
18.631
1.814
14
19.793
1.162
5/8"
10
22.911
20.587
1.814
14
21.749
1.162
3/4"
12
26.441
24.117
1.814
14
25.279
1.162
7/8"
14
30.201
27.877
1.814
14
29.039
1.162
1"
16
33.249
30.291
2.309
11
31.77
1.479
1 1/8"
18
37.897
34.939
2.309
11
36.418
1.479
1 1/4"
20
41.91
38.952
2.309
11
40.431
1.479
1 3/8" 
22
44.323
41.365
2.309
11
42.844
1.479
1 1/2"
24
47.803
44.845
2.309
11
46.324
1.479
1 3/4"
28
53.746
50.788
2.309
11
52.267
1.479
2"
32
59.614
56.656
2.309
11
58.135
1.479
2 1/4"
36
65.71
62.752
2.309
11
64.231
1.479
2 1/2"
40
75.184
72.226
2.309
11
73.705
1.479
2 3/4"
44
81.534
78.576
2.309
11
80.055
1.479
3"
48
87.884
84.926
2.309
11
86.405
1.479
British Standard Pipe Thread - Tapered (BSPT)
 
 
 
Inner
 
 
 
 
 
 
 
Outer
Diameter
 
Threads
Pitch
Thread
Thread
Nominal
Dash
Diameter
Male Thread
Pitch
per
Diameter
Height
Crest
Size
Size
(mm)
(mm)
(mm)
inch
(mm)
(mm)
Rounding
 
 
 
 
 
 
 
 
 
1/16"
01
7.723
6.561
0.907
28
7.142
0.581
0.125
1/8"
02
9.728
8.566
0.907
28
9.147
0.581
0.125
1/4"
04
13.157
11.445
1.337
19
12.301
0.856
0.184
3/8"
06
16.662
14.95
1.337
19
15.806
0.856
0.184
1/2"
08
20.955
18.631
1.814
14
19.793
1.162
0.249
3/4"
12
26.441
24.117
1.814
14
25.279
1.162
0.249
1"
16
33.249
30.291
2.309
11
31.77
1.479
0.317
1 1/4"
20
41.91
38.952
2.309
11
40.431
1.479
0.317
1 1/2"
24
47.803
44.845
2.309
11
46.324
1.479
0.317
2"
32
59.614
56.656
2.309
11
58.135
1.479
0.317
2 1/2"
40
75.184
72.226
2.309
11
73.705
1.479
0.317
3"
48
87.884
84.926
2.309
11
86.405
1.479
0.317
4"
64
113.03
110.072
2.309
11
111.551
1.479
0.317
5"
80
138.43
135.472
2.309
11
136.951
1.479
0.317