NPT Thread Size Chart | Coyote Gear
NPT Amercian Pipe Thread Information:
- NPT is an acronym for National Pipe Thread. NPT threads are tapered. The taper improves joint sealing.
- NPT pipe thread sizes do not correspond to actual inch measurements. For example a 1” NPT Pipe Thread measures 1.315”.
- We hope this information helps people who are new to piping products get the size parts they need.
NPT Pipe Thread Size Chart
| NPT Size | Actual Diameter | Threads Per Inch |
| 1/16" Fittings | 0.3125" | 27 |
| 1/8" Fittings | 0.405" | 27 |
| 1/4" Fittings | 0.540" | 18 |
| 3/8" Fittings | 0.675" | 18 |
| 1/2" Fittings | 0.840" | 14 |
| 3/4" Fittings | 1.050" | 14 |
| 1" Fittings | 1.315" | 11.5 |
| 1-1/4" Fittings | 1.660" | 11.5 |
| 1-1/2" Fittings | 1.90" | 11.5 |
| 2" Fittings | 2.375" | 11.5 |
| 2-1/2" Fittings | 2.875" | 8 |
| 3" Fittings | 3.5" | 8 |
| 4" Fittings | 4.5" | 8 |
NPT Tapered Threads Improve Sealing.
