National Pipe Tapered Fuel (NPTF) (ANSI B1.20.3)
This connection is still widely used in fluid piping systems, even though it is not recommended by the National Fluid Power Association (NFPA) for use in hydraulic fluid power applications. The thread is tapered and the seal takes place by deformation of the threads. The male and female threads connect and a seal is formed when the two are mated together (i.e. threads deformation). This is known as a dry seal thread.
Note: Both the NPTF, NPT, BSPT connectors appear similar, not interchangeable.
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|
Inch size |
Dash size |
Threads per Inch |
Male Thread O.D. (in) |
Female thread O.D (in) | ||
|
1⁄8 |
-2 |
27 |
13⁄32 |
0.41 |
3⁄8 |
0.38 |
|
1⁄4 |
-4 |
18 |
17⁄32 |
0.54 |
1⁄2 |
0.49 |
|
3⁄8 |
-6 |
18 |
11⁄16 |
0.68 |
5⁄8 |
0.63 |
|
1⁄2 |
-8 |
14 |
27⁄32 |
0.84 |
25⁄32 |
0.77 |
|
3⁄4 |
-12 |
14 |
1 1⁄16 |
1.05 |
1 |
0.98 |
|
1 |
-16 |
11 1⁄2 |
1 5⁄16 |
1.32 |
1 1⁄4 |
1.24 |
|
1 1⁄4 |
-20 |
11 1⁄2 |
1 21⁄32 |
1.66 |
1 19⁄32 |
1.58 |
|
1 1⁄2 |
-24 |
11 1⁄2 |
1 29⁄32 |
1.90 |
1 13⁄16 |
1.82 |
|
2 |
-32 |
11 1⁄2 |
2 3⁄8 |
2.38 |
2 5⁄16 |
2.30 |
