How to Remove a Stuck Locknut From a Sink Drain


Locknuts for sink drains are often constructed of a softer metal, such as a zinc-based metal composite that is resistant to corrosion. However, there are certain locknuts on the market that are made of PVC instead. They are quite thin and their only purpose is to provide a watertight barrier between the drain basket and the underneath of the sink. This is true regardless of the material that is used to manufacture them. Once they have been installed, the locknuts will not need to be removed again until the basket has to be replaced or it leaks. This might be the case for decades.

  1. Large pliers with slip-joint joints should be attached to the sides of the locknut. Rotate the nut in a clockwise direction. Maintain a firm grip on the handles at all times as you spin, and try to pull the connection together as much as you can. According to Upgraded Home, you should apply spray lubrication above the locknut so that the lubricant may trickle down into the threads of the fastener. You may make an attempt to release it by rotating the locknut in one direction, then switching directions and turning it in the other direction.

  2. While you are working with the slip-joint pliers, apply heat. According to This Old House, you should apply heat to the locknut by turning a hair dryer to its hottest setting and doing so. Give the locknut several minutes’ worth of exposure to the hot air blowing on it. Make an effort to spin it while the slip-joint pliers are reattached. In the event that the nut cannot be moved with the slip-joint pliers, try heating the locknut and tapping it repeatedly with a hammer. Make another attempt to spin it by gripping it with the slip-joint pliers.

  3. Using a pair of pliers, grab the tabs on the locknut, and then twist them off in opposite directions. The nut will start to crumble as soon as you rip off a tab, so be careful. Keep chipping away at the nut until you can either fully remove it or it starts to come unscrewed.

  4. Put the pointy end of a chisel against one of the locknut tabs, and then use the other end of the chisel to give it a little tap with the hammer. The chisel will start to make cuts into the material as soon as it makes contact, regardless of whether it is plastic or soft metal. Take a chisel and remove the tabs, then use the chisel like a knife and cut the nut vertically and horizontally. After the components have separated, remove the locknut from the drain basket by pulling it off with pliers.

  5. Using a hacksaw, remove the nut from the bolt. Cut through the soft metal or plastic that makes up the locknut in a diagonal direction. After the barrier has been broken, you should remove it. Alternately, if you are not intending to use the drain basket again, you may saw through the drain basket by inserting the hacksaw blade between the locknut and the main part of the sink.

    Things You Will Need

    • Slip-joint pliers, large

    • Spray lubrication

    • Hair dryer

    • Pliers

    • Chisel

    • Hammer

    • Hacksaw


    In lieu of a hair dryer, you may use a heat gun, but you should use caution while doing so. Anything that can catch fire, such as drywall, toilet paper, or tissue can be set ablaze by a heat gun.


    When removing a blocked locknut from a sink drain, you should always use safety glasses to protect your eyes.

    Under no circumstances can a torch be used in the limited area that is found below a sink.