What Size Thread Does a Garden Hose Have?

Having the right thread size to attach your garden hose can save you time and money and make all the difference when irrigating your prized tomatoes or combating a pesky weed. Let's take an in-depth plunge into the world of thread sizes for garden hoses so you can look smart and knowledgeable when shopping for your garden hose.

Thread Sizes: Overview

Threads come in all shapes and sizes. Thread sizes are measured using the American National Standard Pipe Thread (NPT). NPT threads come in two varieties; straight (garden hoses use straight) and tapered, and vary by size. As we will further discuss below, size can matter.

A few of the common thread sizes include 3/8 inch, 1/2 inch, 14NPS, and 15NPS. Threads connect with threading inserts. As a general rule of thumb, male threads screw into female threads. To ensure you get the right parts fit, measure twice and cut once.

3/8 Inch Threads

3/8 inch thread sizes have a 0.675 inch outside diameter, and the thread summit is 0.415 inch. 3/8 inch threads are easy to find and widely available. Although this is a common size, it can also be prone to leakage due to the small diameter and has been used less in recent years.

1/2 Inch Threads

1/2 inch threads have an outside diameter of 0.840 inch, and the thread summit is 0.540 inch. This thread size is more durable and reliable than 3/8 inch threading and has become the industry standard. It works with both standard and pressure fittings and is commonly found in U.S. households.

14NPS and 15NPS Threads

Unlike the two thread sizes mentioned above, NPS stands for National Pipe Size. These pipe sizes are measured by the number of threads per inch instead of the outside diameter measurement. 14NPS has 14 threads per inch, and 15NPS has 15 threads per inch. These threads are more common in American houses built after 1960 and are commonly found in industrial and commercial settings such as irrigation systems or water towers.

Finding the Right Thread Size

While measuring twice and cutting once helps for length, measuring twice is even more important when it comes to thread size. It's no surprise that the wrong thread size can lead to leakage or even worse an inability to connect your hose. So, have a look at the fittings and decide what size is right for you.

Another easy way to check is to take the fitting with you to the store. Ask the personnel for a thread gauge and check which thread size is the right match for you.

Tip: Find the Hex Size

Still stuck? Let's try another method. Run your fingers along the line of the fitting until you find a hex-shaped pattern. Measure the length and width of the hex-shaped pattern, also known as the hex size. Once you have the hex size, you can check a chart of hex sizes to find the thread size that fits.

Comparing Thread Sizes

It's always beneficial to do an apples to apples comparison when shopping. To help you compare thread sizes, we've created a handy chart for you:

Insights

Getting the right fitting in the right size can often bring peace of mind. With this knowledge, you now have the power to go into the store and get the right hose for you without the nagging uncertainty of what size thread you need. Armed and ready with the thread sizes listed above, you can better prepare for your garden hose needs.