Step 5 · Install New Sink Strainer
Take a generous amount of plumber's putty and roll it between your palms to form a rope about 1/2-inch thick and long enough to circle the drain opening. Apply this rope of putty to the underside of the new sink strainer's flange. From the top of the sink, press the new strainer firmly into the clean drain opening. You should see an even ring of putty squeeze out around the edge. From underneath the sink, slide the rubber gasket, followed by the fiber friction washer, and then the large metal locknut over the strainer's body. Hand-tighten the locknut as much as possible. To fully tighten, insert the handles of your channel-lock pliers or a screwdriver into the lugs on the locknut and turn clockwise while holding the strainer basket steady from above to prevent it from spinning. Tighten until the assembly is snug and secure. Use a putty knife or your finger to remove the excess putty that squeezed out inside the sink bowl.