Are you having issues filtering through our thousands of plumbing fittings? Trying to fix that leaky faucet, but don’t know what you need?
Then you’ve come to the right place!
We know fittings can be complicated, and our dedicated staff is here to help, so we’ve created a comprehensive guide to fittings to help get that leaky faucet back up and running.
Fittings don’t have to be frustrating! Let’s start off by explaining exactly what a fitting is.
In the simplest of terms, a fitting is a part that connects two pieces of pipe, or tube together. Essentially, they are the “joints” of your piping system that keep everything connected and functioning as one moving piece.
Fittings are by no means a “one-size fits all” and come in different shapes, sizes and material. Although there are numerous kinds of fittings, most share the same characteristics and serve the same purpose, such as taking one pipe and transitioning it to a different pipe size, or changing the direction in which the pipe is headed.
“Okay, thanks SupplyHouse, but how do I pick one out?”
Well for starters, it helps to know that most plumbing fittings and pipes are measured by the Inside Diameter or ID of the pipe. Plumbing products are primarily concerned with moving liquids from one place to another, so it makes sense to base the measurements on the inside of a pipe, as opposed to the outside diameter, or OD, of the pipe.
For instance, if you have a ½” pipe that you’re looking to get a fitting for – the ½” measurement is an indication of the inside of the pipe. If you measure the outside diameter, or the OD of the pipe, you will calculate a larger measurement that will not help in a fittings selection process and will cause confusion all around.
To keep things simple, the corresponding fittings for a ½” pipe will be categorized as the size of the pipe. For example, if you need an elbow for a ½” pipe, you’ll need a ½” elbow. Of course, the elbow itself will have a different measurement, but that information is irrelevant during a fitting selection process.
“Great! Now that I know fittings are listed by the ID of the pipe I have, how do I read the measurements?”
Good question! As there are multiple styles of fittings, their corresponding measurements will read differently – we’ll get into the measurement readings next time as we introduce you to the different styles of fittings.
See you there!


