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 3/8 (Internal Thread)
| Property |
Minimum |
Maximum |
| Minor Diameter (D1) |
14.95 mm (0.5886 ") |
15.395 mm (0.6061 ") |
| Pitch Diameter (D2) |
15.806 mm (0.6223 ") |
15.931 mm (0.6272 ") |
BSPP G 3/8-A (External Higher precision)
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
16.412 mm (0.6461 ") |
16.662 mm (0.656 ") |
| Pitch Diameter (d2) |
15.681 mm (0.6174 ") |
15.806 mm (0.6223 ") |
BSPP G 3/8-A (External Low precision
| Property |
Minimum |
Maximum |
| Major Diameter (d) |
16.412 mm (0.6461 ") |
16.662 mm (0.656 ") |
| Pitch Diameter (d2) |
15.556 mm (0.6124 ") |
15.806 mm (0.6223 ") |
* For More Threadibg Information go to the BSP Thread Calculator
