Short answer: a garden hose end is 3/4" GHT (also written 3/4"-11.5 NH) — a straight thread, 11.5 threads per inch, that seals against a flat rubber washer. A pipe fitting is 3/4" NPT — a tapered thread, 14 threads per inch, that seals on the thread flanks with tape or dope. The two are almost the same diameter, which is exactly why people force them together and wreck both. You need an adapter, and the one you need is almost always female hose thread × male NPT (FHT × MNPT) or its mirror.
The four numbers that explain everything
Thread standards differ in four ways: diameter, threads per inch, taper, and how they seal. Get any one of them wrong and you get a leak or a cross-thread.
| Thread | Nominal size | TPI | Taper | Seals on | Thread angle |
|---|---|---|---|---|---|
| GHT / NH (garden hose) | 3/4" | 11.5 | Straight | Flat washer in the female end | 60° |
| NPT (US pipe) | 1/2" | 14 | Tapered 1:16 | Thread flanks (tape/dope) | 60° |
| NPT (US pipe) | 3/4" | 14 | Tapered 1:16 | Thread flanks (tape/dope) | 60° |
| NPT (US pipe) | 1" | 11.5 | Tapered 1:16 | Thread flanks (tape/dope) | 60° |
| NPS / NPSH (straight pipe) | 3/4" | 14 | Straight | Gasket or O-ring | 60° |
| BSPP (G, parallel) | 1/2" & 3/4" | 14 | Straight | Bonded washer / O-ring | 55° |
| BSPT (R, tapered) | 1/2" & 3/4" | 14 | Tapered 1:16 | Thread flanks | 55° |
Two traps hide in that table. First, 3/4" NPT and 3/4" BSP share 14 TPI but use different thread angles (60° vs 55°), so they will start and then leak — this is the classic failure with imported pumps and pressure washers. Second, 1" NPT is 11.5 TPI, the same count as 3/4" GHT. If a thread looks coarse, count is not enough; check the diameter too.
How to identify what you have in 60 seconds
- Look at the shape. Hold the male thread against a straight edge. If the crest line is parallel, it is GHT, NPS or BSPP. If it narrows toward the tip, it is NPT or BSPT.
- Look for a washer seat. A female GHT coupling has a flat internal shoulder with a rubber washer sitting in it. Pipe threads never do.
- Count threads over one inch with a rule or a thread gauge. 11.5 in a 1-1/16" male end means GHT. 14 in a roughly 1.05" male end means 3/4" NPT.
- Measure the male outside diameter. 3/4" GHT male measures about 1-1/16" (1.0625") across the crests. 3/4" NPT male measures about 1.050" at the large end and less at the tip — that taper is your tell.
- Check the stamp. Many fittings carry NPT, NH, GHT, G or R marks. G means parallel BSP, R means tapered BSP.
The adapter you need, job by job
| Job | What is on the equipment | Adapter to buy |
|---|---|---|
| Hose bib / outdoor spigot | 3/4" male hose thread (MHT) | None — a hose screws straight on. Add a washer, not tape. |
| Water heater drain valve | 3/4" MHT on the valve body | None — standard garden hose fits. |
| Utility sink / laundry standpipe | 1/2" or 3/4" FNPT | Male hose thread × male NPT nipple, or MHT × MNPT |
| Transfer or sump pump port | 3/4" or 1" FNPT | MHT × MNPT (size to the port, not the hose) |
| Air compressor moisture trap drain | 1/4" FNPT | 1/4" MNPT × FHT, then hose |
| IBC tote outlet | S60x6 coarse buttress (60 mm) | S60x6 × 3/4" MHT tote adapter |
| Pressure washer inlet | 3/4" FHT | None — garden hose feeds it directly |
| Pressure washer outlet / gun | M22 (14 mm or 15 mm insert) or 3/8" QC | M22 × 3/8" quick-connect — check the insert size first |
| Drip irrigation header | 1/2" or 3/4" barb or compression | FHT swivel × barb / compression start connector |
| Rain barrel bulkhead | 3/4" FNPT bulkhead | MNPT × MHT spigot with washer |
Sealing rules that stop 90% of drips
- Never put PTFE tape on a hose thread. GHT seals on the washer. Tape on the crests just holds the faces apart.
- Always put PTFE tape or pipe dope on NPT. Two to three wraps in the direction of tightening, starting one thread back from the tip.
- Hand-tight plus a quarter turn is right for hose threads. NPT wants two to three turns past hand-tight with a wrench — it is a taper, so it keeps getting tighter.
- Replace washers, not couplings. A hardened, flattened washer is the single most common cause of a spigot that weeps.
- Brass to brass or brass to plastic is fine; do not force stainless into a plastic port — the plastic loses.
Quick answers
Is GHT the same as NPS? No. 3/4" NPSH is a straight pipe thread at 14 TPI. It looks parallel like GHT but has a different pitch, so it will not mate with a hose coupling.
Can I just use a 3/4" NPT nipple on my hose? Only through an adapter. The pitch difference (14 vs 11.5) means it will grab for a turn and then bind or leak.
What does FHT × MNPT mean? Female hose thread on one end (it swivels and holds a washer), male pipe thread on the other. It is the single most useful adapter in a yard toolbox.
My pump is metric — now what? If it is stamped G3/4 it is parallel BSP and needs a bonded sealing washer; if it is R3/4 it is tapered BSP. Neither is NPT, and neither is GHT. Buy the labelled BSP-to-GHT adapter rather than forcing it.
Why does my quick-connect leak? Quick-connect garden couplers still rely on the O-ring inside the female half. Pop it out, check for a nick, and replace it — they are a consumable.
Get the right fitting
Our hose fittings, connectors and nozzles collection carries the FHT, MHT and NPT adapters listed above, plus repair couplings and washers. Pair them with a correctly sized garden hose, a drip irrigation header kit, an in-line hose timer, or a rain barrel spigot. Free US shipping on every order.
For the full thread cross-reference, see our hose and irrigation thread reference chart.