1/2 inch NPT Thread Dimensions — ASME B1.20.1
1/2 inch (DN 15) to ASME B1.20.1: Threads — per inch 14 mm; Pitch 1.814 mm; Pipe OD 21.34 mm; Hand-tight 8.13 mm; Effective thread 13.56 mm.
Key to dimensions
1/2 inch NPT Thread Dimensions — ASME B1.20.1 — all dimensions
NPT basic thread dimensions
| Dimension | Value | Equivalent |
|---|---|---|
| Threads — per inch | 14 mm | 0.551 in |
| Pitch | 1.814 mm | 0.071 in |
| Pipe OD | 21.34 mm | 0.840 in |
| Hand-tight — L1 | 8.13 mm | 0.320 in |
| Effective thread — L2 | 13.56 mm | 0.534 in |
| Pitch dia at end — E0 | 19.264 mm | 0.758 in |
| Pitch dia at hand-tight — E1 | 19.772 mm | 0.778 in |
| Tap drill — mm, approx. | 18.26 mm | 0.719 in |
Values are nominal, from NPT Thread Dimensions — ASME B1.20.1. Verify critical dimensions against the current edition of the standard before design, purchase or fabrication.
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1/2 inch NPT Thread Dimensions — ASME B1.20.1: common questions
What are the 1/2 inch NPT Thread Dimensions — ASME B1.20.1?
1/2 inch (DN 15) to ASME B1.20.1: Threads — per inch 14 mm; Pitch 1.814 mm; Pipe OD 21.34 mm; Hand-tight 8.13 mm; Effective thread 13.56 mm.
Does Teshi Group manufacture 1/2 inch forged fittings?
Yes. Teshi Group is an OEM manufacturer in India of forged fittings to ASME B1.20.1, in carbon, alloy, stainless, duplex, super duplex, nickel alloys, titanium and Cu-Ni, with EN 10204 3.1 certificates.
Can I download the 1/2 inch dimensions as a PDF?
Yes. Use “Download PDF for this size” on this page to get a single-size, print-ready PDF with the drawing and every tabulated dimension, or download the full NPT Thread Dimensions — ASME B1.20.1 chart.
Need 1/2 inch forged fittings?
Teshi Group manufactures them in India — send your size, rating and material and get a quote in 24–48 hours.
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