Watering and hoses
GHT vs NPT: why a hose will not screw onto a pipe
A 3/4 inch garden hose fitting and a 3/4 inch pipe fitting look almost the same, but they are built differently and will not seal together. Forcing them can strip threads and still leak.
Updated 26 Oct 2026 · Facts checked against the sources at the end.
Side by side
| GHT (garden hose thread) | NPT (national pipe taper) | |
|---|---|---|
| Threads per inch (3/4 inch size) | 11.5 | 14 |
| Shape | Straight (parallel) | Tapered, tightens as it goes in |
| Seal | Rubber washer against the end of the fitting | The threads themselves, with thread tape or sealant |
| Used on | Hoses, outdoor faucets, sprinklers, nozzles | Plumbing pipe and pipe fittings |
| Male outside diameter | About 1 1/16 inches | About 1 1/16 inches at the start of the taper |
How to tell which one you have
- Look inside the female end: a rubber washer means garden hose thread.
- Count the threads over one inch with a ruler: about 11 and a half means GHT, 14 means NPT.
- Look along the male thread: NPT narrows slightly toward the end; GHT stays the same width.
How to connect them
Use a purpose-made adapter, such as male GHT to female NPT. On the pipe side, wrap thread tape clockwise around the male pipe thread; on the hose side, rely on the rubber washer and hand-tighten. Do not put thread tape on hose threads in place of a washer.
Where people mix them up
- Fitting a hose to a pump, water heater drain or utility sink.
- Building a homemade irrigation manifold from pipe parts.
- Connecting a pressure washer or RV fittings.
In each case, check both ends before you buy parts. More on sizes in garden hose thread size.
Frequently asked questions
Is GHT the same as NPT?
No. At 3/4 inch, GHT has 11.5 threads per inch and a straight thread sealed by a washer; NPT has 14 threads per inch and a tapered thread sealed on the threads.
Can you screw a garden hose onto a pipe thread?
It may start a turn or two but will not seal properly and can damage the threads. Use a GHT to NPT adapter.
Does a GHT fitting need thread tape?
No. GHT seals with a rubber washer. Thread tape is for tapered pipe threads like NPT.
Related
Sources
Written in our own words from the sources above. See our editorial policy. Spotted a mistake? Tell us.