NPSM thread Fitting size chart

Date:Apr 02, 2020

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