BSB British Standard Brass Thread. Used brass tubing. BSB has a 26 TPI pitch through the whole range.
The flank angle is 55°.
| Nominal Dia. |
TPI |
Pitch mm |
Tap/Drill mm |
| G 1/16” |
6.561 |
28 |
0.907 |
| G 1/8” |
8.565 |
28 |
0.907 |
| G 1/4” |
11.445 |
19 |
1.337 |
| G 3/8” |
14.95 |
19 |
1.337 |
| G 1/2” |
18.633 |
14 |
1.814 |
| G 3/4” |
24.12 |
14 |
1.814 |
| G 1” |
30.292 |
11 |
2.309 |
| G 1 1/4” |
38.953 |
11 |
2.309 |
| G 1 1/2” |
44.846 |
11 |
2.309 |
| G 2” |
56.657 |
11 |
2.309 |
| G 2 1/2” |
72.227 |
11 |
2.309 |
| G 3” |
84.927 |
11 |
2.309 |
| G 4” |
110.073 |
11 |
2.309 |
| G 5” |
135.473 |
11 |
2.309 |
| G 6” |
160.873 |
11 |
2.309 |
| Nominal Dia. |
Diameter inch |
Diameter mm |
— |
| G 1/16” |
0.063 |
7.722 |
— |
| G 1/8” |
0.125 |
9.728 |
— |
| G 1/4” |
0.25 |
13.157 |
— |
| G 3/8” |
0.375 |
16.662 |
— |
| G 1/2” |
0.5 |
20.955 |
— |
| G 3/4” |
0.75 |
26.441 |
— |
| G 1” |
1 |
33.249 |
— |
| G 1 1/4” |
1.25 |
41.91 |
— |
| G 1 1/2” |
1.5 |
47.803 |
— |
| G 2” |
2 |
59.614 |
— |
| G 2 1/2” |
2.5 |
75.184 |
— |
| G 3” |
3 |
87.884 |
— |
| G 4” |
4 |
113.03 |
— |
| G 5” |
5 |
138.43 |
— |
| G 6” |
6 |
163.83 |
— |
