National Pipe Straight Mechanical (NPSM)
Both male and female NSPM connectors' threads are straight, The female fitting has an inverted 30°seat, A mechanical connection is made when the both male and female are mated together. The tapered seat creates a leak-resistant connection, and are commonly found in fluid power systems. A properly chamfered NPTF male will also seal with the NPSM female.
Note: A NPSM female can seal together with a chamfered NPTF male.
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 | 14 | 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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