On Jul 21, 4:40*pm, "
wrote:
On Jul 21, 11:16*am, Limp Arbor wrote:

I need to add a trap to my cast iron drain in my basement.

I'm going to remove my 4" cleanout and run the trap into that fitting.

Here's the difficulty:
My cleanout plug is threaded into a bushing held into the bell end of
a cast fitting. *The threaded cleanout is a little shy of 4" (about 3
15/16) *I bought a 4" threaded male PVC fitting but it is about 4 1/4..

Do they make a threaded PVC fitting that will go into a 4" female
steel?

Should I just remove the bushing and get the rubber boot that will let
me go from the bell end of the cast down to 4" PVC?

Very strange. *AFAIK, all pipe fittings are based on inside diameter.
So the 4" PVC you have should go into the 4" cleanout threads.
Given that you say it misses by about 5/16 or so, ...


Not exactly. My existing brass cleanout plug is about 3 15/16.

A 4" PVC cleanout plug or threaded male fitting is about 4 1/4.