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 5/8 (Internal Thread)
| Property |
Minimum |
Maximum |
| Minor Diameter (D1) |
20.588 mm (0.8106 ") |
21.129 mm (0.8319 ") |
| Pitch Diameter (D2) |
21.749 mm (0.8563 ") |
21.891 mm (0.8619 ") |
BSPP G 5/8-A (External Higher precision)
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
22.627 mm (0.8908 ") |
22.911 mm (0.902 ") |
| Pitch Diameter (d2) |
21.607 mm (0.8507 ") |
21.749 mm (0.8563 ") |
BSPP G 5/8-A (External Low precision
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
22.627 mm (0.8908 ") |
22.911 mm (0.902 ") |
| Pitch Diameter (d2) |
21.465 mm (0.8451 ") |
21.749 mm (0.8563 ") |
* For More Threadibg Information go to the BSP Thread Calculator
