BSP Sizing Explained
BSP sizing can be confusing since the reference size does not relate to the physical measurement.
For example a male thread which physically measures 26mm or just over 1" would logically be thought of as 1" BSP, but is not! This thread would be referred to as 3/4" BSP.
Use the table below to translate between BSP trade references and the physical measurement.
|
BSP Trade Size |
Major Diameter (Physical Measurement) |
|
|
Inch |
mm |
|
|
1/8" |
0.383 |
9.728 |
|
1/4" |
0.518 |
13.157 |
|
3/8" |
0.656 |
16.662 |
|
1/2" |
0.825 |
20.955 |
|
3/4" |
1.041 |
26.441 |
|
1" |
1.309 |
33.249 |
|
1 ¼" |
1.65 |
41.91 |
|
1 ½" |
1.882 |
47.803 |
|
2" |
2.347 |
59.614 |
|
2 ½" |
2.96 |
75.184 |
|
3" |
3.46 |
87.884 |
|
4" |
4.45 |
113.03 |
