Basic Thread Dimensions
*Â The below values are nomoinal (without tolerances) and are valid for both external and internal threads.
| Thread Family |
BSPP (G) |
| Relevant Standards |
ISO 228-1, ISO 228-2 |
Tolerances for all Classes
BSPP G 1 1/2 (Internal Thread)
| Property |
Minimum |
Maximum |
| Minor Diameter (D1) |
44.846 mm (1.7656 ") |
45.486 mm (1.7908 ") |
| Pitch Diameter (D2) |
46.324 mm (1.8238 ") |
46.504 mm (1.8309 ") |
BSPP G 1 1/2-A (External Higher precision)
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
47.443 mm (1.8678 ") |
47.803 mm (1.882 ") |
| Pitch Diameter (d2) |
46.144 mm (1.8167 ") |
46.324 mm (1.8238 ") |
BSPP G 1 1/2-A (External Low precision
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
47.443 mm (1.8678 ") |
47.803 mm (1.882 ") |
| Pitch Diameter (d2) |
45.964 mm (1.8096 ") |
46.324 mm (1.8238 ") |
* For More Threadibg Information go to the BSP Thread Calculator
