Garden Hose Threading Basics

Surprisingly, garden hose threading is a pretty complicated topic. Depending on where you live, your threading could be drastically different between your pipes and hose, and this can be further complicated by poor fittings. Questions like "are garden hose threads NPT" may seem like gibberish, but they're actually quite important to getting the proper adaptors and fittings. So we're breaking down how to unscrew tight hose fittings, threading details, and more.

What's on the docket today?

Today's Topics Include:

• The garden hose will not unscrew
• Is a garden hose thread the same as a pipe thread?
• Are garden hose threads NPT?
• What size are garden hose threads?
• Are all garden hose fittings the same size?
• What size connector is a garden hose?
• Which way does a hose unscrew?
• How do I loosen a stuck garden hose?
• How do you loosen a nozzle on a hose?

Now, let's waste no more time and just get into things.

Threading & Garden Hoses 101

Let's start with a problem we've all had at some point or another - no matter how hard you pry, your garden hose just won't come loose ! After that, we can talk nitty-gritty threading all you like.

The Garden Hose Will Not Unscrew

If your garden hose will not unscrew, I've got good news for you - it's not the end of the world. However , just a warning that you may end up needing a hacksaw by the end of this, assuming the first tries don't work, so... there's that.

To remove a garden hose from the threading on your faucet, begin by using a wrench and/or pliers to loosen the connector. If that fails, try again, but with the *magical* goop - WD-40.

Should all else fail , you can take a hacksaw to the hose's coupling. Make a small cut large enough for a flathead screwdriver to fit in, and pry the coupling loose. Worst case you can cut through the whole thing and unscrew the remaining piece of coupling.

Be very careful not to cut through the spigot - you're trying to sever and replace the hose, not your entire spigot.

Is a Garden Hose Thread the Same as a Pipe Thread?

Garden hose threads and most pipe threads are not the same size. While this will vary based on where you live, at least in the UK, you'll likely need a thread adaptor to fit the tap to your hose.

Generally, pipe threads are tapered (at a sharper angle) and garden hose threads are your bog-standard mostly horizontal threading. Keep reading for a technical breakdown in the next section.

What Size Are Garden Hose Threads?

In the U.K. (and everywhere that's not North America), there are two standard threadings - BSPP (British Standard Pipe Parallel) and BSPT (British Standard Pipe Tapered).

BSPP is used for garden hoses, generally a 3/4 inch BSPP connector. Older taps may use a 1/2 inch BSP connector, and farms, factories, and horticulture (pretty much anything that needs lots of water) use a 7/8 inch threading.

In the United States and Canada, however, it gets much more complicated. Standard threading for garden hoses is GST, whereas most taps/spigots use NPT connectors that range between 1/2" - 3/4", with multiple types of threading in various spacing. If you're in the U.S., your best bet is to bring a piece of an old hose of the same size and try it out on various adaptors in a hardware or DIY store.

Alternatively, you can go to your local hardware store and... ask for help. I know it hurts to even think about but believe it or not, the people working there do this for a living and will be very helpful in your journey.

Are Garden Hose Threads NPT?

No, garden hose threads are not NPT.

For the uninformed, National Pipe Taper (NPT) is the United States' standard for measuring tapered threads on pipes and fittings. NPT threads are not interchangeable with National Pipe Straight (NPS) threading or GHT, which is commonly used in garden hoses.

Other names for NPT include ANSI/ASME B1.20.1 (but who wants to say that mouthful) and Male Pipe Threads (MPT).

The U.K. uses BSPP and BSPT threading, as detailed below, making this process much easier.

Are All Garden Hose Fittings the Same Size?

No, all garden hose fittings are not the same size. This varies both by country and the application of the tap to which you're trying to connect the hose. Read the two sections above for more information.

What Size Connector Is a Garden Hose?

Most garden hose connectors are 3/4" or 1/2" connectors and will require an adaptor so they can connect to the tapered threading of most taps.

Which Way Does a Hose Unscrew?

Hoses universally unscrew clockwise, a.k.a. right, no matter where you live . This is one of those things that (thankfully) the Americans didn't decide to change for no discernable reason.

How Do I Loosen a Stuck Garden Hose?

Now, we talked about this above. The general idea is to do your utmost to ensure you're freeing it with pliers and/or a wrench, rather than a hacksaw.

You can use various products like WD-40 (my favourite), CLR (calcium, lime, and rust remover, with which I have zero experience), or even PAM cooking spray to loosen the connection if you're running into issues.

How Do You Loosen a Nozzle on a Hose?

Loosening a nozzle on a hose can be done in a few ways. If you're using a Quick Disconnect Connector (QDC), you'll need to muscle it free and buy a new, better one. They're designed to be efficient and idiot-proof for safe disconnection of air, liquid, and gas lines - so if it's not working, it's likely broken.

If it's attached with threading, though, you can use the above tips of a wrench, pliers, and WD-40. Another thing you can do now that you're not right next to your house is to use a quick temperature change to loosen the fitting. This works well on a number of threaded devices, and is done as follows:

1. First, read this peer-reviewed paper on the mathematical model for temperature-induced loosening… I’m kidding. But it is interesting and relevant, though…
2. Now – drain the hose from the faucet end and roll it up. Bring the hose and nozzle to your freezer.
3. Pop your hose and nozzle in the freezer for a few minutes. This is because cold causes metal to contract – just remember that cold is bad for your hose, so don’t forget it.
4. Remove the nozzle from the freezer, try again gently with a wrench and/or pliers, and twist. It should come loose.
5. Now just repeat the process until the nozzle is free.

You're now a chemist - you're welcome!

Conclusion

All in all, the threading for your home's pipes and your garden hose is surprisingly complicated. And if you're in the United States or Canada, things get far more in-depth than they need to be. You've got to look for specific adaptors in just the right size, or else you run the risk of a failed trip to the hardware store - every dad's worst nightmare.

If you end up running into a stuck hose coupling, always start with pliers, a wrench, and WD-40. Worst case, pop that sucker in the freezer (very briefly). Be sure to check out our guide to garden hose repair for more useful reading!