Once you understand how to use it, it will become an indispensable part of yourplumbing tool kit.

Standard wrenches and pliers are almost useless in this situation.

Enter the basin wrench.

Closeup of a basin wrench on a hardwood floor

The Spruce / Adrienne Legault

What Is a Basin Wrench?

A basin wrench is a specialty plumbing tool with a rotating, self-adjusting gripping head and long handle.

It is used to tighten and remove the mounting nuts of faucet tailpieces.

Applying lubricant to the nut

The Spruce / Adrienne Legault

The design makes the tool functional in tight spaces where other tools can’t reach.

The head swiveled 180 degrees in either direction to set it up for loosening or tightening nuts.

At the bottom end of the shaft is a sliding T-bar that provides leverage for turning the shaft.

Adjusting the wrench head

The Spruce / Adrienne Legault

Because it is designed only for use on faucet mounting nuts, a basin wrench’s uses are limited.

If this is the case, a preliminary spray with a penetrating oil can be a good idea.

Wait a few minutes for the oil to penetrate before attempting to loosen the nut.

Using the basin wrench to turn the nut

The Spruce / Adrienne Legault

If you get it backward, the claw will slip off the nut immediately.

(In this photo, the head is positioned for loosening the nut.)

Even if you use the tool only a couple of times, buying makes more sense than renting.

Telescoping basin wrench

The Spruce / Aaron Stickley

Clean it after each use by wiping it with a clean cloth.

An occasional spray of light machine oil on the pivoting joint is a good idea.

If any corrosion develops, wipe the tool down with a cloth moistened with oil.

Store it in a dry location.

With bare minimum maintenance, you should never need to buy a second basin wrench.