How to Install or Replace a Kitchen Sink Strainer

Kitchen sink strainers wear out. The rubber seal cracks, the basket gets bent, water starts leaking where it shouldn't. Replacing one is one of the first jobs that teaches you the actual geometry of your sink—how it connects, where the water really goes—and it's work you can absolutely do yourself with nothing fancy. The strainer sits in the drain opening and catches solids before they get to the p-trap. When it fails, you either live with a leaking cabinet or you fix it. This job is genuinely simple, just follow the sequence: take apart from below, pull out the old one, clean the hole, set the new one in putty, bolt it down, reconnect the tailpiece. One thing to know: you'll be working upside down under the sink with a wrench. Bring a bucket and old towels. The water that comes out is usually gray and smells like your drain, so prepare for that.

1. Stop the Flow First. Close the shut-off valves under the sink or at the main line. Remove everything stored in the cabinet—cleaning supplies, trash, anything underneath. Lay down an old towel on the floor to catch what will leak. Position a bucket or small basin directly under the tailpiece (the part that connects the strainer to the p-trap). There will be standing water in the trap.
2. Loosen the Connection. Locate where the tailpiece screws into the p-trap fitting below. Use a wrench to hold the fitting steady with one hand while you turn the compression nut counterclockwise with the other hand. Loosen it enough to pull the tailpiece away and break the seal. Water will drain into your bucket. Set the disconnected tailpiece aside on the towel.
3. Unbolt from Below. Look up at the underside of the sink. You'll see the locking ring (a large ring-shaped nut) that holds the strainer in place, and often a friction ring or locknut backing it. Use an adjustable wrench or basin wrench to hold the friction ring steady while you turn the locking ring counterclockwise. If there's no friction ring, use a second wrench to stabilize while you turn. Turn until the locking ring comes completely free. You may need to tap it gently with a hammer if corrosion is heavy.
4. Extract the Old Strainer. Go to the sink top. Push up from below to pop the old strainer out of the hole, or pull from above if it's loose. The rubber or putty seal will resist slightly. Once it's out, you'll see old plumber's putty or a rubber gasket stuck to the underside of the sink rim around the hole. Scrape all of it away with a putty knife or old chisel. Get down to clean metal or porcelain. This step matters—new putty won't seal properly over old residue.
5. Clean Every Trace. Wipe the entire drain hole and the rim around it with a damp cloth. Dry it completely with a towel. Remove any bits of old putty or gasket material with your fingernail or a plastic scraper. The surface should be clean and dry—moisture under the putty creates a leak. If the chrome or porcelain is corroded, that's fine; putty will still seal to it.
6. Rope the Flange. Open a can or package of plumber's putty. Knead it briefly between your hands until it's soft and uniform in color. Roll a rope of putty about ½ inch in diameter and long enough to circle the drain hole once. Press this rope around the underside flange of the new strainer. The putty should be continuous and stick to the metal without gaps. You want a complete seal ring that will compress when you bolt the strainer down.
7. Seat with Pressure. From above the sink, insert the new strainer into the hole with the flange facing down and the putty rope touching the underside rim. Press down firmly and wiggle it side to side to seat it evenly. The flange should sit flush against the sink surface. Some putty will squeeze out around the edges—that's normal and you'll clean it later. The strainer should not rock or move when you press on it.
8. Bolt Down Firmly. Go under the sink. Slide the friction ring (or locknut) up onto the threaded tailpiece of the strainer, then thread the locking ring up after it. Hand-tighten the locking ring first so you can feel when it's started correctly. Once it's hand-tight, use your wrench to tighten it the rest of the way. Use one wrench to hold the friction ring steady and another to turn the locking ring clockwise. Tighten until it's snug—don't over-tighten, which can crack the sink rim or strip the threads.
9. Rejoin the Trap. Take the tailpiece you set aside earlier and thread it back into the p-trap fitting hand-tight. Use your wrench to hold the fitting steady and turn the compression nut clockwise to tighten. Tighten until snug. The fit should be finger-tight plus about a quarter turn with a wrench. This connection does not need to be cranked down—gentle pressure creates a better seal than over-tightening.
10. Verify No Leaks. Fill the sink basin with water to about 2 inches. Let it sit for 30 seconds, then slowly drain it while watching underneath from your bucket vantage point. Check the seam where the strainer body meets the sink rim, the threads where the locking ring connects, and the tailpiece connection. Water should not drip or run. If you see a leak at the rim, go back to step 7 and press the strainer down harder—the putty needs more compression. If the tailpiece leaks, tighten the compression nut another quarter turn.
11. Finish Clean. Once you've confirmed no leaks during the drain test, restore water pressure by opening the shut-off valves. Use the sink normally for a minute or two, then inspect again from below for any new leaks. If the test is clear, go to the sink top and use a putty knife to scrape away the excess putty that squeezed out around the strainer rim. Wipe the rim with a damp cloth and dry it. Any putty left on the surface will harden and look messy.