[[TitleIndustry]]

NPTF thread Fitting size chart

Date:Apr 02, 2020

National Pipe Tapered Fuel (NPTF)

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.

 

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


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