How to Use a Basin Wrench

Basin wrench
Amazon.com

A basin wrench is a specialty plumbing tool that nearly all professional plumbers own—and one that every homeowner who does DIY plumbing work should own. The tool is designed to do only one thing—to install or remove a faucet—but it does that one thing better than any other tool. Once you understand how to use it, it will become an indispensable part of your plumbing tool kit. 

Kitchen and bathroom sink faucets typically are secured with low-profile mounting nuts that are accessible only on the underside of the sink, behind the basin. Standard wrenches and pliers are almost useless in this situation. Enter the basin wrench.

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

Basin Wrench vs. Channel-Lock Pliers

Many DIYers find themselves reaching for long-handled channel-lock pliers (also known as channel-type pliers or slip-joint pliers) when tightening or untightening the mounting screws on faucet tailpieces.

With their long handles, channel-lock pliers can work in a pinch, but it is much harder to grip faucet mounting nuts with this tool. Most intermediate to experienced DIYers who do occasional plumbing work will want to own a basin wrench as well as channel-lock pliers

Basin Wrench
  • Does one job, but does it very well

  • Self-adjusting gripping head

  • Rotating gripping head is perpendicular to handle during use

Channel-Lock Pliers
  • A more versatile tool, with many uses

  • Jaws must be manually adjusted

  • Gripping head is a straight-line extension of the handles

Parts of a Basin Wrench

A basin wrench has a pivoting gripping head that sits at the end of a long handle, and it is designed to reach up into that awkward, inaccessible space behind a sink to tighten or loosen the mounting nuts on a faucet or the flexible supply tube nuts that connect to the end of the faucet tailpieces. These nuts are so difficult to reach that some plumbers prefer to attach the faucet to the sink before setting the sink into place. Where this isn't possible, though, the basin wrench lets you reach up behind the sink from underneath to grip the mounting nuts and tighten or loosen them easily.

The tool has a long shaft and a small, spring-loaded, claw head that tightens onto the nut as you turn the shaft. 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. 

Because it is designed only for use on faucet mounting nuts, a basin wrench's uses are limited. But from time to time, every homeowner faces faucet replacement, and when you need one, a basin wrench will prove to be the best $10 or $20 you ever spent. 

How to Use a Basin Wrench

  1. Apply Lubricant to Mounting Nut (Optional)

    A faucet that has been in place a long time may have mounting nuts that are frozen in position with corrosion. If this is the case, a preliminary spray with a penetrating oil can be a good idea. A spray can of oil with an extension straw is ideal for applying a small burst of oil onto the threads of the mounting bolt. Wait a few minutes for the oil to penetrate before attempting to loosen the nut.

  2. Adjust the Wrench Head

    Pivot the head of the basin wrench so it is perpendicular to the shaft and faces the correct position for loosening or tightening the nut:

    • To loosen the nut, you will turn the wrench counterclockwise, and the opening of the claw on the head should be on the right (left photo). 
    • To tighten the nut, you will turn the wrench clockwise; the opening of the claw should be at the left (right photo). 

    Remember, turning clockwise tightens; turning counterclockwise loosens. Or, if you prefer: righty-tighty, lefty-loosey. Also, remember that you're viewing the nut from the perspective of looking up at it from under the sink—not from the top looking down.

    You'll know that you've positioned the head correctly if the claw grips the nut as you turn the wrench in the desired direction. If you get it backward, the claw will slip off the nut immediately. 

    Using a basin wrench
    Aaron Stickley
  3. Turn the Nut

    Fit the head of the wrench around the faucet mounting nut so the ridged jaws of the claw grip the notches or edges of the nut. (In this photo, the head is positioned for loosening the nut.) Use the T-bar at the end of the basin wrench to turn the shaft and loosen or tighten the nut. You may have to use two hands on the T-bar, or you can slide the bar all the way to one side and lever it with one hand while stabilizing the wrench shaft with the other hand. 

    How to use a basin wrench
    Aaron Stickley

    Tip

    In some cases, the nut and shank might be so rusted that you will have to cut the faucet out from above the sink. This is tedious work using a reciprocating saw or hacksaw, and it requires a good level of skill as to not damage your sink or countertop.

    Tips for Using a Basin Wrench

    It doesn't take long to get the hang of using a basin wrench, but here are a few tips for difficult situations: 

    • A telescopic basin wrench (left photo) has an extendable shaft to reach faucets mounted behind extra-deep sink basins. 
    • Use a pipe or the back end of an adjustable wrench to increase your leverage on a T-bar (right photo) for removing stubborn nuts. There's no need for this kind of leverage when tightening a nut.  
    • The claw can grab a nut from any position around the nut (just like pliers can), so move the head to any position that's comfortable for turning the wrench. 
    Telescoping basin wrench
    Aaron Stickley

    Renting vs. Buying

    While it is theoretically possible to rent a basin wrench at a home center or tool rental outlet, there's almost no financial advantage to doing so. Hand tools generally rent for about $10 per day, and a good basin wrench can be purchased for $15 to $20 (though you can spend $50 or more on a contractor-level telescoping basin wrench). Even if you use the tool only a couple of times, buying makes more sense than renting.

    How to Maintain Your Basin Wrench

    Basic care of a basin wrench is similar to that of any metal hand tool. 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.