BSP Thread Fittings
Pipe thread sizes are based on the inside diameter (ID) or flow size. The most common global pipe thread forms are:
- NPT American Standard Pipe Taper Thread
- NPSC American Standard Straight Coupling Pipe Thread
- NPTR American Standard Taper Railing Pipe Thread
- NPSM American Standard Straight Mechanical Pipe Thread
- NPSL American Standard Straight Locknut Pipe Thread
- NPTF American Standard Pipe Thread Tapered (Dryseal)
- BSPP British Standard Pipe Thread Parallel
- BSPT British Standard Pipe Thread Tapered
| Advertised size - Inside diameter | Outside Diameter (inches) | Outside Diameter (mm) | Comments |
|---|---|---|---|
| 1/8" | ~ 3/8 " | ~ 9.5 mm | NOT the same as NPT |
| 1/4" | ~ 1/2 " | ~ 13 mm | NOT the same as NPT |
| 3/8" | ~ 5/8 " | ~ 16.5 mm | NOT the same as NPT |
| 1/2" | ~ 7/8 " | ~ 20.5 mm | NOT the same as NPT |
| 3/4" | ~ 1 " | ~ 24 mm | NOT the same as NPT |
