Short answer
Unscrew the coupling nut and the locknut under the sink, push the old strainer up and out, and scrape off the old putty. Lay a pencil-thick rope of plumber’s putty (or stain-free putty or silicone on stone) under the flange of the replacement, press it into the hole, and from below fit the rubber gasket, friction ring and locknut in the order your kit shows. Snug it evenly without overtightening, wipe the squeeze-out, reconnect the tailpiece and trap, and fill the sink to check for leaks.
Before you start
Check what the replacement needs to match. Most US kitchen sinks have a 3-1/2 inch drain hole (Houzer) and a 1-1/2 inch tailpiece (HomeGuide). Thick cast iron, fireclay and composite sinks need a strainer body long enough for the locknut to reach. If the bowl has a garbage disposal, you need a disposal flange instead, not a basket strainer. Our kitchen sink drain buying guide covers the styles, and the size guide shows how to measure.
What you need
- Replacement basket strainer kit for a 3-1/2 in opening; check sink thicknessFind it
- Plumber’s putty stainless steel sinksFind it
- Stain-free putty or 100% silicone granite, quartz, marble, compositeFind it
- Spud wrench or large slip-joint pliers for the locknutFind it
- Slip-joint pliers for the coupling and slip nuts
- Plastic putty knife scrapes old putty without scratching
- Penetrating oil for a stuck locknut
- Bucket and rags for the water in the trapFind it
- Slip joint washers in case the old ones are flat or crackedFind it
How to replace a kitchen sink drain, step by step
Remove the trap and disconnect the tailpiece
Put a bucket under the sink. Loosen the slip nuts on the P-trap and remove it, then unscrew the coupling nut that joins the tailpiece to the bottom of the strainer. Pull the tailpiece down and set it aside.
Loosen the old locknut
Turn the large locknut on the underside of the strainer counterclockwise with a spud wrench or big slip-joint pliers. Have someone hold the basket from above, or wedge pliers handles through it, so the strainer does not spin. If the nut is seized, spray penetrating oil on the threads, wait, and try again.
Push out the old strainer
Once the locknut, friction ring and gasket are off, push the strainer body up through the hole from below and lift it out.
Scrape off the old putty
Clean the rim of the drain hole with a plastic putty knife, then wipe it with a rag until the surface is bare and dry. Clean the underside of the hole too, where the gasket will sit.
Apply putty or silicone under the flange
Roll plumber’s putty into a rope about as thick as a pencil and press it around the underside of the strainer flange. On granite, quartz or composite sinks, use a stain-free putty (Oatey makes one for stone) or a bead of 100 percent silicone instead, as Ruvati notes.
Set the strainer in the hole
Press the strainer straight down into the drain hole so the putty spreads evenly under the flange. Line up any logo or the basket post the way you want it.
Fit the gasket, friction ring and locknut
From below, slide the rubber gasket up the strainer body against the sink, then the fiber friction ring, then thread on the locknut by hand. Most kits use this order, but follow the order shown in your kit.
Tighten evenly, without overtightening
Have a helper hold the strainer from above so it stays centered and does not turn. Tighten the locknut until it is snug and the gasket is compressed evenly. Do not crank it: Ruvati warns that overtightening can crack a sink, and plastic bodies can split.
Wipe away the squeeze-out
Putty will squeeze out around the flange on top. Wipe it off with a finger and a rag. Silicone needs the cure time on its label before the sink gets wet.
Reconnect the tailpiece and trap
Fit the tailpiece to the bottom of the strainer with its washer and coupling nut, then refit the P-trap. Replace any flattened or cracked slip washers. Tighten plastic nuts by hand plus a little more.
Leak test
Close the basket, fill the sink, and look underneath with a flashlight and a dry paper towel. Then pull the basket and let the full bowl drain, which tests every joint under flow, the check The Home Depot describes. Tighten any joint that weeps a quarter turn at a time.
Common problems
Leak at the locknut. Usually the gasket is not seated evenly, the putty is thin in one spot, or the nut needs a little more turn. If tightening does not stop it, take the strainer out, clean, and reset it with fresh putty.
Leak at the coupling nut. The tailpiece washer is missing, flat or crooked. Reseat or replace it.
Leak lower down. A slip nut on the P-trap is loose or its washer is worn. While it is apart, consider a fresh trap kit if the old one is cracked or corroded.
The strainer spins when you tighten. Have a helper hold it from above, or wedge the handles of a pair of pliers into the basket crossbar and hold those.
Related jobs
Doing the bathroom too? See how to replace a bathroom sink drain. If the drain was slow before you started, clean the trap while it is off and read how to unclog a kitchen sink. If the pipes under the sink do not line up with the replacement, ask a licensed plumber.
Questions people ask
How do I loosen a stuck kitchen sink locknut?
Spray the threads with penetrating oil and give it time to soak. Then turn the locknut counterclockwise with a spud wrench or large slip-joint pliers while a helper holds the basket from above so the strainer does not spin. Tapping the locknut lugs with a hammer and screwdriver can break it free.
Should I use plumber’s putty or silicone on a kitchen sink drain?
Plumber’s putty is the usual choice on stainless steel sinks. On granite, quartz and other stone or composite sinks, standard oil-based putty can stain, so use a stain-free putty or 100 percent silicone. Follow the sink maker’s instructions.
What order do the gasket and friction ring go in?
In most kits the rubber gasket goes against the underside of the sink, then the fiber friction ring, then the locknut. Instructions differ between brands, so follow the order shown in your kit.
How tight should a kitchen sink strainer locknut be?
Snug and even, so the gasket compresses and the strainer cannot turn, but no tighter. Overtightening can crack the sink or a plastic strainer body. If it leaks, tighten a little more rather than cranking it.
Do I need to replace the tailpiece too?
Not always. If the old tailpiece is corroded, thin or does not reach the trap, replace it at the same time. Some strainer kits include one; check before you start.
Sources
Last reviewed October 12, 2026. Parts, sizes and listings change; check the product details before you buy, and follow the maker’s instructions.