Hydraulic fittings
BSPP Thread Chart
Reference geometry rows for BSPP thread identification. Use with physical pitch and sealing checks.
Last updated 2026-05-12Confidence: reference-derived4 rows
| Nominal | Dash | Thread type | Pitch / TPI | Major diameter | Seal |
|---|---|---|---|---|---|
| 1/8 | parallel | 28 TPI | 0.383 in / 9.728 mm | washer | |
| 1/4 | parallel | 19 TPI | 0.518 in / 13.157 mm | washer | |
| 3/8 | parallel | 19 TPI | 0.656 in / 16.662 mm | washer | |
| 1/2 | parallel | 14 TPI | 0.825 in / 20.955 mm | washer |