3/4" NPT Thread Size
Complete thread specifications for 3/4 inch NPT threads. Common in residential water supply, HVAC systems, and industrial applications requiring moderate flow capacity.
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NPT threads follow ASME B1.20.1 standard with 1:16 taper
Note: This page shows 3/4" NPT dimensions. Use the dropdown above to explore other sizes.
Thread Specifications
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3/4" NPT Thread Specifications
The 3/4 inch NPT thread is the second most common residential pipe size, offering approximately 40% more flow area than 1/2" NPT. With 14 threads per inch and a major diameter of 1.0500", it's ideal for main water supply lines and high-demand fixtures.
Key Dimensions
- Major Diameter: 1.0500" (26.67 mm)
- Minor Diameter: 0.9765" (24.80 mm)
- Pitch Diameter: 1.0131" (25.73 mm)
- Threads Per Inch: 14 TPI
- Drill Tap Size: 59/64" (23.42 mm)
Common Applications
- Residential: Main water service entry, irrigation system mains, whole-house filters
- Commercial: Water heater connections, boiler feed lines, cooling tower piping
- HVAC: Chilled water lines, hot water heating distribution, glycol loops
- Industrial: Process water, chemical dosing systems, compressed air headers
Assembly Guidelines:
- Clean and inspect threads for damage or debris
- Apply 4-5 wraps of Teflon tape or pipe dope to male threads
- Hand-tighten 4 full turns
- Wrench-tighten 2 additional turns (torque: 20-30 ft-lbs for steel)