Bathroom | January 5, 2023

How To Install A Lock Nut Sink Strainer (Do It In 3 Steps!)

How To Install A Lock Nut Sink Strainer (Do It In 3 Steps!)

If you notice a hole around your sink drain hole, you might be able to fix it by simply loosening the strainer from underneath and applying fresh plumber’s putty under the lip.

Often, however, the sink strainer itself is corroded. It might even break apart as you pry it open. What do you do then? I’m going to show you how to install a sink strainer so you don’t have to call a plumber.

Thankfully, a sink strainer replacement is simple and inexpensive.

What is a Sink Strainer?

In case you’re unfamiliar, a sink strainer is the metal sieve that keeps food and other debris from entering your drain. It looks like a mesh strainer and works as a filter for your sink.

install sink strainer - different types
There are all sizes and styles of sink strainers. But they have a common function: they keep debris (that can cause clogs) from falling into your drain system.

Common Types of Sink Strainers

There are two common kinds of basket strainers. One type is secured by a lock nut, while the other is held by a plastic retainer and three screws. The lock-nut type is generally used for stainless-steel sinks because the lock nut tightens against the sink without bending the metal. But I’ll tell you how to install both.

install sink strainer - diagram of parts
This is a view (from underneath the sink) of the main parts of a lock-nut style strainer after it has been installed. The tissue is being used to detect any leaks from the lock nut (in case it was not tightened securely enough).

Install Sink Strainer (Lock-Nut)

1. Remove the Old Strainer

  • Firstly, turn off the water supply to your sink faucet.
  • Then, loosen and remove the faucet tailpiece.
  • Unscrew the locknut that secures the strainer body to the sink. If the strainer body starts to turn in the sink while you loosen the locknut, wedge a screwdriver into the drain and hold it steady with your free hand (this is much easier to do with an assistant). See photo below.
install sink strainer - unscrew the lock nut
Unscrewing the lock not can be awkward if the strainer’s body begins turning while you’re trying to loosen it. Try this trick with a pair of plier handles and a screwdriver to hold the body still while the pipe wrench unscrews the lock not. A friend is really helpful for this part.

2. Stop Leaks Around the Strainer

  • If water leaks from around the sink opening, replace the putty and, if necessary, the strainer.
  • Push the strainer body out of the sink from underneath.
  • Scrape the putty from the drain hole, and remove the old strainer if you plan to reuse it. Note that some strainers come with adhesive-coated rubber gaskets and therefore need no putty.

3. Install the Sink Strainer

  • Lower the strainer body in the sink opening from above.
  • From underneath the sink, slip the rubber and metal washers over the neck of the strainer, then secure the lock nut. You might need a 14″ pipe wrench to tighten the strainer in place.
  • Raise the tailpiece into place and tighten the coupling nuts.
  • Scrape away any excess putty around the sink opening with a putty knife. Be careful not to scratch the surface.

Install Sink Strainer (Retainer-Type)

The process is much the same for a retainer-type installation. So follow the above process, but do this instead:

  • Put the puttied strainer body into the opening.
  • Attach the rubber and metal washers from underneath (same as with the lock nut above).
  • Fit the reainer onto the strainer body and turn it until the ridges on the side of the drain fit into the grooves of the reainer.
  • Twist to lock it in place, then tighten the retainer screws.
  • Connect the tailpiece as you would for a lock nut strainer.

Final Thoughts

In conclusion, it’s fairly simple to install a lock nut sink strainer in just 3 steps. These instructions along with a video on how to complete this project are easy to follow along to. Just make sure that you have the right tools and equipment with you to complete the project.

If your new strainer comes with a gasket, you might not need the plumber’s putty. But if you need it, here’s a video on how to do it. You can also read our plumber’s putty instructions here.

Call 1-Tom-Plumber

In addition, don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you need help with replacing or installing a sink strainer.

1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.

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