How to Use a Basin Wrench?

One of the most useful tools in any plumber’s toolbox is without a doubt the basin wrench. This humble tool is specifically designed for removing or installing the difficult-to-access mounting nuts located directly under the faucet of your sink.

If you’ve ever installed or removed an old faucet in a bathroom or kitchen, you’re probably familiar with the frustration of trying to access the mounting nut with a regular pair of pliers. Firstly, the mounting nut is located above and behind the sink basin, and is often in a tight space that’s difficult or impossible to reach comfortably.

Luckily, the basin wrench makes this job much easier by allowing you to tighter or loosen the nut from a distance.

Let’s take a closer look at this useful tool in more detail – so you’ll be able to do your own faucet and sink plumbing without calling in an expensive plumber.

What is a basin wrench?

A basin wrench is a plumbing tool with a spring-loaded pivoting wrench head and a long slim handle. It typically features a T-bar handle which allows you to operate the tool with leverage from below.

The tool’s head typically swivels 180 degrees – which not only allows you to position it to fit whatever mounting nut you’re dealing with but also ensures you can both loosen and tighten the nut. The long shaft can either be telescopic or one-piece, but is typically at least 10 inches long.

The basin wrench used in this post is the Tekton 11 Inch Basin Wrench. It’s a well-engineered and reasonably priced tool and makes a great option for most bathroom and kitchen sinks.

How to Use a Basin Wrench – Guide

Step 1: Setup and Position the Wrench

Before you start cranking at that stubborn mounting nut, you’ll need to set up the wrench so it’s ready to use. Keep in mind a basin wrench can be swiveled around and used either clockwise for tightening or counterclockwise for loosening a mounting nut.

basin wrench under sink

In order to access the mounting nut, you may need to first remove the flexible water supply tubes connected to the faucet tailpieces. This will free up enough space to get the claw head into the narrow space directly underneath the faucet.

Next, position the claw head perpendicular to the shaft facing the correct position for either tightening or loosening the nut. You’ll know you’ve positioned the wrench correctly when the wrench grips the nut as you rotate it in the desired direction, and comes loose as you rotate it in the opposite direction.

Step 2: Loosen (or Tighten) the Mounting Nut

loosening mounting nut with basin wrenchNow that you’ve set up the wrench, it’s time to turn the T-bar handle to loosen or tighter the mounting nut. If you’re loosening a stubborn nut, you may find that it’ll require some coaxing to get it loose. This is especially true for older mounting nuts that have become corroded or rusted.

Extend the T-bar all the way to one side to increase your leverage when loosening the basin wrench. If you’re still having trouble, you can try clamping a small pair of vise grip pliers to the end of the T-bar to create more leverage. This should only be done when loosening a stubborn nut and isn’t necessary for tightening.

Another way to loosen a corroded nut is by applying some penetrating oil. This will work its way into the threads and help lubricate a sized mounting nut.


Even if you’re not a plumber, you’ll probably get the hang of using a basin wrench in a short period of time. The wrench’s long handle and ratcheting claw head give the required reach and leverage to loosen even the most stubborn mounting nuts.

That said, you may still run into some issues with particularly stubborn or difficult-to-access mounting nuts.

  • If you still reach the mounting nut with a standard basin wrench, you may need to get yourself a telescopic wrench. This will give you a few extra inches of reach to get to those particularly difficult-to-access mounting nuts.
  • In a cramped sink, you may need to remove the P-trap in order to free up enough space to get your arm and wrench in place.
  • If you’re dealing with a stubborn corroded mounting nut and penetrating oil isn’t getting the job done, you may need to cut out the faucet from above the sink. This is a more labor-intensive job and will require you to cut through the threaded tailpiece with a reciprocating saw or hand saw.
  • If you’re installing a new sink or replacing an old one, and you’re having a hard time reaching below the basin to secure the mounting nut to the threaded tailpiece, there is an alternative. You can install the faucet directly to the sink before you set the sink in place. This will save you the headache of doing it later on and is the preferred method of many plumbers and contractors.

Denis Gardner

I've loved tinkering and fixing things for as long as I can remember. So, naturally, I gravitated towards DIY and home improvement when I bought my first home. Nowadays you can find me writing about my passions or messing around with my newest tool!

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