What Threads Are On A Garden Hose: Sizes, Standards & Tips

What threads are on a garden hose? In the U.S., 3/4-11.5 GHT (NH) straight threads.

If you have ever asked what threads are on a garden hose, you are not alone. I work with hoses and fittings in the field, and I see the same mix-ups every season. This guide explains what threads are on a garden hose in clear terms, with real examples and pro tips you can use today.

Garden hose threads explained

Garden hose threads are the ridges that let the hose and faucet lock together. In North America, they are straight threads, not tapered. The seal comes from a flat rubber washer, not from the threads. If you wonder what threads are on a garden hose, this is the key idea that prevents leaks.

Key facts you should know:

• The common North American size is called GHT or NH.
• The official spec is 3/4-11.5 GHT (also written 3/4-11.5 NH).
• Straight threads seal with a washer; do not rely on tape for the seal.

Standards that define these parts:

• ASME B1.20.7 for garden hose coupling straight threads.
• ASME B1.20.1 for NPT tapered pipe threads.
• ISO 228-1 for BSPP (parallel) threads used outside North America.
• ISO 7-1 for BSPT (tapered) pipe threads used outside North America.

Regional thread types and sizes

When people ask what threads are on a garden hose, the answer depends on where they live. Here is how it breaks down by region.

United States and Canada

• Thread type: GHT or NH, straight thread.
• Size: 3/4-11.5 GHT.
• Seal method: Flat washer in the female coupling.
• Notes: Hose bibbs on homes are male GHT. Hose ends are female GHT.

United Kingdom and most of Europe

• Thread type: BSPP (parallel), often called G threads.
• Common sizes: 1/2 inch BSP, 3/4 inch BSP, 1 inch BSP.
• Seal method: Washer or O-ring in the connector.
• Notes: Quick-connect systems (like Hozelock or Gardena) screw onto BSP thread adaptors.

Australia and New Zealand

• Thread type: BSPP on most outdoor taps and adaptors.
• Common sizes: 3/4 inch BSP, with adaptors to 1 inch or 1/2 inch.
• Seal method: Washer or O-ring.

Why this matters:

• GHT 11.5 TPI will not match 3/4 BSP 14 TPI.
• Mixing these can cross-thread and leak.

How to identify your hose thread at home

If you ask what threads are on a garden hose at your home, use this quick check.

Steps:

• Look for 3/4 stamped on the metal coupling. In North America, that hints at 3/4 GHT.
• Count threads per inch. GHT has 11.5 TPI. BSP 3/4 has 14 TPI.
• Measure the outside diameter with a ruler. 3/4 GHT is about 1.06 inches across.
• Check the seal style. If a flat washer makes the seal, you likely have straight threads.
• Try a known adaptor. A 3/4 GHT to 1/2 NPT adaptor will test if you have GHT.

Pro tip from the field:

• I keep a pocket pitch gauge and a small caliper in my truck. It turns guesswork into a 30-second ID.

Adapters, reducers, and making parts fit

A big part of what threads are on a garden hose is how to adapt them. You may need to connect GHT to NPT or to BSP. That is normal in repairs and upgrades.

Useful adaptors to keep on hand:

• 3/4 GHT male to 1/2 NPT female. Good for pumps and filters.
• 3/4 GHT female to 3/4 NPT male. Good for water timers and pipes.
• 3/4 GHT to 3/4 BSP. Useful for EU quick connectors on US taps.
• 3/4 GHT Y-splitter. Adds two outlets from one tap.

Rules for sealing:

• Straight threads (GHT, BSPP): Use a washer or O-ring. Do not depend on tape for the seal.
• Tapered threads (NPT, BSPT): Use PTFE tape or pipe dope on the threads.

Real-world note:

• In my installs, a GHT-to-NPT adaptor is the single most used part. It saves the day when a new timer has NPT, but the tap is GHT.

Common problems and how to fix them

Not knowing what threads are on a garden hose causes most leaks and cracks I see. Here are fast fixes.

• Drip at the swivel: Replace the flat washer. Check that the washer is seated and not cracked.
• Cross-threaded coupling: Stop and realign. Hand-tight first, then a small turn with pliers if needed.
• Persistent leak on NPT connection: Add two to three wraps of PTFE tape and retry.
• Stuck metal-on-metal joint: Use a strap wrench. Avoid over-torque, which can oval the fitting.
• Plastic quick-connect leak: Swap the O-ring and add silicone grease on the seal.

Mistakes to avoid:

• Forcing BSP onto GHT. It may bite, but it will leak and damage threads.
• Using tape on GHT as the only seal. The washer does the work.
• Over-tightening. A crushed washer seals worse, not better.

Buying guide: choose the right hose, bibb, and fittings

Before you buy, confirm what threads are on a garden hose at your home, shop, or garden. Then match every part in the chain.

Checklist:

• Confirm region and thread type. GHT/NH in North America, BSP elsewhere.
• Size match. 3/4 is most common; 1/2 and 1 inch exist in some systems.
• Washer quality. Choose heavy-duty rubber or EPDM. Keep spares.
• Material choice. Brass lasts longer than thin aluminum. Nylon is light and kind to threads.
• Quick-connects. Use brand-matched sets to prevent small O-ring mismatch.

My setup for clients:

• Brass 3/4 GHT fittings at the tap.
• A GHT Y-splitter with shutoffs.
• A small kit of GHT-to-NPT and GHT-to-BSP adaptors.
• A pouch of washers, O-rings, and PTFE tape.

Advanced notes for pros and tinkerers

For those who want the fine print on what threads are on a garden hose, here are deeper specs.

Helpful spec points:

• GHT/NH threads are straight with a 60-degree profile and 11.5 TPI.
• 3/4 BSPP has a 55-degree profile and 14 TPI.
• Major diameters are close, which fools many people at first glance.
• Sealing face geometry matters. Flat-face with washer differs from cone-face seats.

Testing a mystery fitting:

• Use a thread pitch gauge for TPI.
• Test-fit with a known GHT cap and washer. If it runs on smooth and seals hand-tight, you likely have GHT.
• If it binds early, check for BSP or NPT.

Practical use cases and setups

Knowing what threads are on a garden hose helps with special jobs. These are common cases I handle.

• Rain barrels: Many come with BSP taps. A BSP-to-GHT adaptor lets you use US hoses.
• Pressure washers: Machine ports are often NPT; hoses are GHT. Keep a GHT-to-NPT adaptor ready.
• RV and marine: Fresh water inlets use GHT for hoses. Filters may use NPT.
• Irrigation timers: Bodies can be NPT, but the hose connectors are GHT. Read the label and adapt.

Simple rule I teach teams:

• Know the thread. Pick the seal type. Then tighten by hand and test under flow.

Maintenance tips that prevent leaks

Teach your crew what threads are on a garden hose, and care gets easy. A little upkeep saves water and time.

Easy habits:

• Rinse grit from threads before you connect.
• Replace washers at the first sign of drip.
• Grease O-rings with food-grade silicone once a season.
• Store hoses out of sun. UV makes plastic and rubber brittle.
• In winter, drain and cap ends to keep debris out.

What I keep in my caddy:

• Assorted flat washers and O-rings.
• PTFE tape for tapered joints.
• A strap wrench and small pliers.
• A GHT cap to test seals fast.

Frequently Asked Questions

What threads are on a garden hose?

In the U.S. and Canada, it is 3/4-11.5 GHT (NH) straight thread. It seals with a flat washer, not the threads.

Is GHT the same as NPT?

No. GHT is straight and uses a washer. NPT is tapered and seals on the threads with tape or pipe dope.

Can I connect BSP to GHT?

Yes, with the right adaptor. Do not force them together without an adaptor, since the pitch and angle differ.

Do I need PTFE tape on a garden hose?

Not for GHT-to-GHT joints, since a washer seals them. Use tape only on tapered threads like NPT or BSPT.

How do I measure my hose thread?

Count threads per inch and measure diameter. GHT is about 1.06 inches major diameter with 11.5 TPI.

Why does my new hose still leak?

Check the washer. Replace a hard, cracked, or missing washer, then hand-tighten and test again.

Are quick-connects universal?

No. Many brands fit well together, but O-ring sizes vary. Match systems or use adaptors for best results.

Conclusion

You now know what threads are on a garden hose and how they seal. GHT in North America, BSP in many other places, with adaptors to bridge the gaps. With the right washer, the proper adaptor, and a light touch, your setup will stay dry and solid.

Put this guide to work today. Check your fittings, swap a few washers, and add the adaptors you lack. Want more tips like this? Subscribe, share your setup in the comments, or ask a question for your next project.