3 inch NPT Thread Dimensions — ASME B1.20.1
3 inch (DN 80) to ASME B1.20.1: Threads — per inch 8 mm; Pitch 3.175 mm; Pipe OD 88.90 mm; Hand-tight 19.46 mm; Effective thread 30.48 mm.
Key to dimensions
3 inch NPT Thread Dimensions — ASME B1.20.1 — all dimensions
NPT basic thread dimensions
| Dimension | Value | Equivalent |
|---|---|---|
| Threads — per inch | 8 mm | 0.315 in |
| Pitch | 3.175 mm | 0.125 in |
| Pipe OD | 88.90 mm | 3.50 in |
| Hand-tight — L1 | 19.46 mm | 0.766 in |
| Effective thread — L2 | 30.48 mm | 1.20 in |
| Pitch dia at end — E0 | 84.852 mm | 3.34 in |
| Pitch dia at hand-tight — E1 | 86.068 mm | 3.39 in |
| Tap drill — mm, approx. | 82.55 mm | 3.25 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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3 inch NPT Thread Dimensions — ASME B1.20.1: common questions
What are the 3 inch NPT Thread Dimensions — ASME B1.20.1?
3 inch (DN 80) to ASME B1.20.1: Threads — per inch 8 mm; Pitch 3.175 mm; Pipe OD 88.90 mm; Hand-tight 19.46 mm; Effective thread 30.48 mm.
Does Teshi Group manufacture 3 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 3 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 3 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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