Tubing sizes: Kitchen, vanity, toilet

[Luv2Q]

Am I correct in understanding that typical tubing sizes are as follows?
... Kitchen sink: 1/2"
... Vanity sink: 3/8"
... Toilet: 3/8"
... Ice maker: 3/8"

Reason for my question: I want to have shutoff valves for all fixtures. I realized I just wasn't too sure of tubing sizes. If it matters, my supply lines to these fixtures is 1/2" copper pipe branching off 3/4" copper main. Stubouts will all have 1/2" male adapters.

Thx in advance (& sorry if I'm asking really dumb questions .. just couldn't find anything with the Search function).

[LazyPup]

A 3/8" supply tube is generally used for the following items although a 1/4" is sometimes required under special circumstances.

Kitchen sink
Dishwasher
Lavatory (vanity sink)
Watercloset (toilet)
Utility sink
Laundry tub faucet


Ice makers typically have a 1/4" supply tube although some have a 3/8" supply.

Installing male thread adapters on copper pipe stub outs can present some problems. If the thread adapter is installed on the pipe during rough-in phase it will require making much larger holes in the sheetrock to fit over the pipe. One the other hand, it is extremely difficult to solder thread adapters on the stub outs without scorching the paint or wall surface during the trim-out phase.

The preferred method is to use compression type angle stop valves which are simply tightened in place with a pair of wrench's so their is very little risk of damaging the finish wall.

Here is a tip, compression fittings are generally sized for tubing, not pipe. Pipe is identified by its outside diameter while tubing is identified by its inside diameter.

1/2" copper pipe has an inside diameter of approximately a 1/2" while the outside diameter is 5/8" therefore when selecting compression fittings to fit on 1/2" copper pipe you look for "5/8comp" or "1/2FIP" (female iron pipe)

[Luv2Q]

Great info, LazyPup! And the info on compression-type shutoff valves is a big help, too. As always, I'm constantly amazed at the high quality of the advice you provide this forum.

Thanks very much!