Is there a smaller size that's standard? I pulled out a broken bathtub drain insert because it was broken, and the standard 1-1/2 inch size does not fit. Is there another standard size that fits maybe older homes? The house was built in 2002, but it looks to be a pretty standard shower/tub insert.

The thing is the 1-1/2 inch tub stopper DOES fit through the hole in the tub but not in the actual pipe below (it's too big to thread in). Any ideas?

  • If you're referring to the little threaded bit on the bottom of the stopper which screws down into the drain, then there are 2 "standards" - 3/8" and 5/16"...
    – brhans
    Commented Mar 25, 2018 at 12:42
  • We had a cheap drain plug that didn't fully seal when closed, took a long time to drain when open, was constantly getting clogged. So I removed it, and we use a rubber stopper. Commented Mar 25, 2018 at 13:53
  • IM guessing it's 3/8 since the store had only 1-1/2 but none of those fit.
    – msmith1114
    Commented Mar 26, 2018 at 3:21

1 Answer 1


You also find drain assemblies with 1-1/4" tailpieces, but they're almost exclusively used for sinks. They're used with a 1-1/2" to 1-1-/4" reducer since the PVC drain plumbing usually won't be smaller than 1-1/2".

The diameter of the actual threaded drain assembly isn't smaller in these cases. They fit the sink/tub the same way. Just the tailpiece is smaller.

Post photos of your situation for more specific advice.

  • Well it's def for a bathtub, and the stopper is def a bathtub stopper. I (the twist ones). unfortunately I threw the old one away :/
    – msmith1114
    Commented Mar 26, 2018 at 3:21

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