Identification sheet
The three pipe-thread families, by trade size. The trade size is neither the thread diameter nor the bore, which is why a 1/4 in pipe thread measures about 13 mm across the threads.
32 rows3 sectionsLandscape
| Size | Thread | TPI / pitch | Basic major Ø | Measured across crests | Tube OD | Working pressure |
|---|---|---|---|---|---|---|
| American National Pipe Taper, NPT (ASME B1.20.1) and NPTF dryseal (ASME B1.20.3) | ||||||
| 1/16 NPT | 1/16-27 NPT | 27 TPI (0.941 mm pitch) | 7.94 mm / 0.313 in | Not published | Not published | Not published |
| 1/8 NPT | 1/8-27 NPT | 27 TPI (0.941 mm pitch) | 10.29 mm / 0.405 in | 9.9 mm to 10.41 mm | Not published | 5,000 psi (345 bar) |
| 1/4 NPT | 1/4-18 NPT | 18 TPI (1.411 mm pitch) | 13.72 mm / 0.54 in | 13.2 mm to 13.9 mm | Not published | Not published |
| 3/8 NPT | 3/8-18 NPT | 18 TPI (1.411 mm pitch) | 17.15 mm / 0.675 in | 16.6 mm to 17.3 mm | Not published | Not published |
| 1/2 NPT | 1/2-14 NPT | 14 TPI (1.814 mm pitch) | 21.34 mm / 0.84 in | 20.6 mm to 21.6 mm | Not published | 3,000 psi (207 bar) |
| 3/4 NPT | 3/4-14 NPT | 14 TPI (1.814 mm pitch) | 26.67 mm / 1.05 in | 26 mm to 27 mm | Not published | 2,500 psi (172 bar) |
All 32 rows across 3 sections, black on white, column headers repeating at the top of every page, banded rows, no row split across a page break, landscape. Print it or save it as a PDF.
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Every value on this page was checked against 14 independent published sources: