Plumbing Basics

Ever hear the term capillary fitting and wonder if it had something to do with blood vessels? Don’t worry—it’s strictly plumbing. But it does involve a tight connection. Let’s talk about copper capillary fittings and why they’ve stood the test of time.

 
What Are Copper Capillary Fittings?
Copper capillary fittings are soldered pipe connectors that rely on a process called capillary action. That’s when molten solder flows into the narrow gap between the fitting and the pipe by surface tension.

Here’s how it works:

Heat the joint
Apply solder to the edge
The solder is drawn into the joint, creating a sealed connection
It’s a strong, watertight bond—no screws, clamps, or compression needed.

What Makes a Fitting “Capillary”?
The design is what makes these fittings so effective:

The fitting has an internal socket slightly larger than the pipe
When heated, this tight gap allows solder to flow in naturally
The result is a clean, compact, and permanent joint
Capillary fittings are also called

Hiya, it’s Plumb—your favorite plumbing mascot with a heart of gold and a toolkit full of wisdom. Today, we’re diving into a classic plumbing essential: copper fittings. Whether you're a seasoned pro or a first-time fixer-upper, this one's for you.

So, what are copper fittings? Let’s start with the basics.

What Exactly Are Copper Fittings?
Copper fittings are the connectors used to join pieces of copper pipe together in a plumbing system. They're the elbows, tees, couplings, and adapters that help your water go where it's supposed to—without leaks or drama.

They're made from copper, a metal known for its strength, corrosion resistance, and ability to carry hot and cold water safely.

Think of copper fittings as the joints in a skeleton: they let everything bend, turn, and flow naturally.

What Types of Copper Fittings Are There?
Copper fittings come in many shapes and sizes. Here are the most common ones:

Elbows – Change direction (usually 45 or 90 degrees)

Tees – Split flow into three directions