Material Composition: Fittings from forged or cast pressure resistant carbon steel with a zinc-trivalent anti-corrosion coating
NPT and NPSM are pipe thread. NPSM is straight while NPT is tapered. Female National Pipe Straight Mechanical (NPSM) fittings incorporate a 30° seat against the male creating a metal leak resistant connection
Pipe Thread Size NPTF and NPSM Sizes
American Dryseal Pipe Threads (NPTF and NPSM)is used connection incorporates two methods of sealing. The male NPTF (Dryseal) tapered thread will mate with the NPTF tapered female which is usually a port and seal when the special threads are crushed together. Male PTF (Short Dryseal) are identical to male NPTF threads except that the thread lengths have been shortened by one full thread from the small end of the taper. Additional sealing aids such as pipe dope and Teflon tape are often used with these threads. If the male has a 30 degree seat it will mate with the 30 degree cone seat in the NPSM straight thread swivel female usually found on adapters and is mechanically held together by the threads. NPTF and NPSM are not interchangeable with the British pipe threads.
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Dash Size
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Inch Size
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Thread Size
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Male Thread (O.D)
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Female Thread (I.D.)
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2
|
1/8"
|
1/8-27
|
.41
|
.37
|
|
4
|
1/4"
|
1/4-18
|
.54
|
.49
|
|
6
|
3/8"
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3/8-18
|
.68
|
.62
|
|
8
|
1/2"
|
1/2-14
|
.84
|
.76
|
|
12
|
3/4"
|
3/4-14
|
1.06
|
.98
|
|
16
|
1"
|
1-11.5
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1.31
|
1.24
|
|
20
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1 1/4"
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1 1/4-11.5
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1.66
|
1.58
|
|
24
|
1 1/2"
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1 1/2-11.5
|
1.90
|
1.82
|
|
32
|
2"
|
2-11.5
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2.38
|
2.29
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