Do they make 1 1/4 inch tees to connect double sinks to a single drain? If not what can you do to connect?

Hi Brad, Yes they do. It's called a "continuous waste". A continuous waste is usually used to connect the tubs of a kitchen sink to a single wall stubout so they come in 1 1/2". However they are easily adaptable to double bath room lavatorys by the use of nylon gaskets that reduce the waste to 1 1/4". A countinuous waist connects to one lavatory direct and runs over to the branch, (the middle opening) of a tee. The top end of the tee ties into the second lavatory while the bottom end connects into a "P" trap which then connects to the wall stub out. A continuous waste comes in two flavers. Chrome over brass and PVC. Hope this answers your question. Tom

It could depend on what you are working with. Most sink drains are chromed brass tubing or PVC. My sink adapts from 1 1/2'' brass to copper pipe and then a "Y" connecting the 2. I think 1 1/4'' may be more common now. Look around at your hardware or home center stores. If you can't find the "T" you need in 1 1/4'', you may have to bush up to 1 1/2''. The further down you go before teeing, the less problem you may have with water dumped down one sink coming up in the other.

Drain vs pressure
Fittings specially made for drains will have a larger radius and be more than 90 degrees so a vertical pipe can connect to a pipe that slopes down a little. They may be hard to find except in the larger sizes of brass and PVC.

Pipe vs Tubing
Pipe may mean NPT. Pipe thread sizes are ID. A 1 1/4 pipe is slightly over 1 1/4'' inside and about 1 1/2'' outside. Tubing usually is thinner walled, and is sized by the OD.