Side-by-Side Comparison
Pipe Threads
Garden Hose Thread vs. NPT Pipe Thread
Comparing 2 standards across 11 specifications. 11 key differences identified.
Comparing:
Garden Hose Thread
NPT Pipe Thread
Garden Hose Thread (GHT) is the standardized North American outdoor water coupling governed by ANSI/ASME B1.20.7. Specified as 3/4"-11.5 NH, it features a straight, non-tapered thread with a 1.0625-inch (27.0 mm) major diameter that seals via axial compression against a flat rubber washer inside the female swivel coupling.
NPT (National Pipe Taper) is the standard North American tapered pipe thread governed by ANSI/ASME B1.20.1. Featuring a 60° thread flank angle and a 1:16 taper rate (0.75 inches per foot), NPT achieves sealing through flank wedging and deformation, requiring PTFE tape or pipe sealant to prevent spiral leak paths.
Specification Comparison Table
11 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Governing Body
|
ANSI / ASME B1.20.7 | ANSI / ASME B1.20.1 |
|
Thread Form & Flank Angle
|
60° American National straight parallel thread | 60° symmetric truncated V-thread |
|
Sealing Mechanism
|
Flat elastomeric washer compressed in female swivel seat | Thread flank interference fit + PTFE tape / anaerobic sealant |
|
Thread Designation
|
3/4"-11.5 NH (National Hose) | — |
|
Major Diameter (Male Outer ø)
|
1.0625 inches (27.0 mm) | — |
|
Thread Pitch / TPI
|
11.5 TPI (2.209 mm pitch) | — |
|
Operating Water Pressure
|
40–80 PSI typical residential (up to 150 PSI burst) | — |
|
Taper Ratio
|
— | 1:16 (0.75 in/ft or 1° 47' with centerline) |
|
Common Pitches (TPI)
|
— | 1/8": 27 TPI | 1/4"-3/8": 18 TPI | 1/2"-3/4": 14 TPI | 1"-2": 11.5 TPI |
|
Max Working Pressure @ 23°C (73°F)
|
— | Up to 5,000–10,000 PSI (dependent on pipe schedule/fitting) |
|
Primary Geographical Region
|
— | United States, Canada, and Mexico |