11.   If you tighten the nuts with all your strength you can damage the drain.

12.   In a plastic joint, the flange fits directly into the mouth at the top of the trap and is held in place by tightening the nut.

13.   The washer is then slid down into the mouth of the trap, and the nut is tightened to hold the assembly in place.

14.   Tightening the nut on the end of the rod will firm up the post.

15.   Tighten the nuts with a wrench.