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.
