Don’t fall into the trap of thinking that just because the thread measures say ¾" that it is a ¾" BSP. It is probably a ½" BSP.
For those of you trying to get your head around BSP fittings we offer the table below to help you.
A list of 15 thread sizes are defined by the BSP standards, ranging from BSP1/16 to BSP6. The BSP size number was originally based on the inner diameter measured in inches (25.4 mm) of a steel tube for which the thread was intended, but is in the modern metric version of the standard simply a size number.
BSP Thread |
Threads |
Pitch |
Major diameter |
Gauge |
Corresponding pipe |
|||||
[mm] |
[in] |
DN |
OD |
OD |
Thick- |
|||||
1/16 |
28 |
0.907 |
7.723 |
0.304 |
4 |
|||||
1/8 |
28 |
0.907 |
9.728 |
0.383 |
4 |
6 |
10.2 |
0.40 |
2 |
|
1/4 |
19 |
1.337 |
13.157 |
0.518 |
6 |
8 |
13.5 |
0.53 |
2.3 |
|
3/8 |
19 |
1.337 |
16.662 |
0.656 |
6.4 |
10 |
17.2 |
0.68 |
2.3 |
|
1/2 |
14 |
1.814 |
20.995 |
0.825 |
8.2 |
15 |
21.3 |
0.84 |
2.6 |
|
3/4 |
14 |
1.814 |
26.441 |
1.041 |
9.5 |
20 |
26.9 |
1.06 |
2.6 |
|
1 |
11 |
2.309 |
33.249 |
1.309 |
10.4 |
25 |
33.7 |
1.33 |
3.2 |
|
1¼ |
11 |
2.309 |
41.910 |
1.650 |
12.7 |
32 |
42.4 |
1.67 |
3.2 |
|
1½ |
11 |
2.309 |
47.803 |
1.882 |
12.7 |
40 |
48.3 |
1.90 |
3.2 |
|
2 |
11 |
2.309 |
59.614 |
2.347 |
15.9 |
50 |
60.3 |
2.37 |
3.6 |
|
2½ |
11 |
2.309 |
75.184 |
2.960 |
17.5 |
65 |
76.1 |
3.00 |
3.6 |
|
3 |
11 |
2.309 |
87.884 |
3.460 |
20.6 |
80 |
88.9 |
3.50 |
4 |
|
4 |
11 |
2.309 |
113.030 |
4.450 |
25.5 |
100 |
114.3 |
4.50 |
4.5 |
|
5 |
11 |
2.309 |
138.430 |
5.450 |
28.6 |
125 |
139.7 |
5.50 |
5 |
|
6 |
11 |
2.309 |
163.830 |
6.450 |
28.6 |
150 |
165.1 |
6.50 |
5 |
|
