NPSM is NATIONAL PIPE STRAIGHT MECHANICAL thread standard ANSI/ASME B1.20.1 , NPT is National Standard Taper Pipe Threads ANSI B1.20.1, NPTF is National Pipe Thread Fuel standards ANSI B 1.20.3, BSPT is British Standard Pipe Taper thread AS 1722.1, BS 21, ISO 7, these are different thread standards.
NPSM and NPTF is the American Dryseal Pipe Threads, but difference is as follows:
NPSM thread is formerly known as NPS, it often used in the Female Pipe Swivel was designed with 60° flank angle. The NPSM female pipe swivel seats on a 30° seat will mate with male thread end.
NPTF thread is American pipe thread for fuel standards, 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.
American Dryseal Pipe Threads (NPTF and NPSM) | ||||||
Dash Size | Inch Size | Thread | Male Thread O.D. mm | Male Thread O.D. inches | Female Thread I.D. mm | Female Thread I.D. inches |
2 | 1/8 | 1/8 - 27 | 10.3 | .41 | 9.4 | .37 |
4 | 1/4 | 1/4 - 18 | 13.7 | .54 | 12.4 | .49 |
6 | 3/8 | 3/8 - 18 | 17.3 | .68 | 15.7 | .62 |
8 | 1/2 | 1/2 - 14 | 21.3 | .84 | 19.3 | .76 |
12 | 3/4 | 3/4 - 14 | 26.9 | 1.06 | 24.9 | .98 |
16 | 1 | 1 – 11-1/2 | 33.3 | 1.31 | 31.5 | 1.24 |
20 | 1-1/4 | 1-1/4 – 11-1/2 | 42.2 | 1.66 | 40.1 | 1.58 |
24 | 1-1/2 | 1-1/2 – 11-1/2 | 48.3 | 1.90 | 46.2 | 1.82 |
32 | 2 | 2 – 11-1/2 | 60.4 | 2.38 | 57.9 | 2.29 |
NPT thread is American Taper Pipe Thread, with sealant compound. National Pipe Taper (1:16)
The flank angle is 60°. NPT male thread will mate with NPT female thread port.
NPT - American Standard Pipe Thread Taper 1) | ||||||
Pipe Size (inches) | TPI | Approximate Length of Thread (inches) | Approximate Number of Threads to be Cut | Approximate Total thread Makeup, Hand and Wrench (inches) | Nominal Outside Diameter Pipe OD (inches) | Tap Drill (inches) |
1/16" | 27 | 0.313 | ||||
1/8" | 27 | 3/8 | 10 | 1/4 | 0.405 | R |
1/4" | 18 | 5/8 | 11 | 3/8 | 0.540 | 7/16 |
3/8" | 18 | 5/8 | 11 | 3/8 | 0.675 | 37/64 |
1/2" | 14 | 3/4 | 10 | 7/16 | 0.840 | 23/32 |
3/4" | 14 | 3/4 | 10 | 1/2 | 1.050 | 59/64 |
1" | 11-1/2 | 7/8 | 10 | 9/16 | 1.315 | 1-5/32 |
1-1/4" | 11-1/2 | 1 | 11 | 9/16 | 1.660 | 1-1/2 |
1-1/2" | 11-1/2 | 1 | 11 | 9/16 | 1.900 | 1-47/64 |
2" | 11-1/2 | 1 | 11 | 5/8 | 2.375 | 2-7/32 |
2-1/2" | 8 | 1 1/2 | 12 | 7/8 | 2.875 | 2-5/8 |
3" | 8 | 1 1/2 | 12 | 1 | 3.500 | 3-1/4 |
3-1/2" | 8 | 1 5/8 | 13 | 1 1/16 | 4.000 | 3-3/4 |
4" | 8 | 1 5/8 | 13 | 1 1/16 | 4.500 | 4-1/4 |
4 1/2" | 8 | 5.000 | 4-3/4 | |||
5" | 8 | 1 3/4 | 14 | 1 3/16 | 5.563 | 5-9/32 |
6" | 8 | 1 3/4 | 14 | 1 3/16 | 6.625 | 6-11/32 |
8" | 8 | 1 7/8 | 15 | 1 5/16 | 8.625 | |
10" | 8 | 2 | 16 | 1 1/2 | 10.750 | |
12" | 8 | 2 1/8 | 17 | 1 5/8 | 12.750 | |
14" | 8 | 14.000 | ||||
16" | 8 | 16.000
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BSPT Whitworth Pipe Thread for pipes and fittings. Parallel female thread and tapered male thread (taper 1 : 16). An appropriate sealing compound can be used in the thread to ensure a leak-proof joint. The flank angle is 55°. BSPT male thread will mate with BSPT female thread port.
Hydraulic fittings adapter often is designed with NSPM, NPT, NPTF and BSPT combination types, you need more info, please contact us now.