[JoeT]

I need to replace the water supply hose for a toilet. The complication I'm having is that I'm not sure of the diameter on the end that connects to my shut off valve. I've tried to measure as best I can and it seems to be slightly wider than 1/2". I'm also not sure if replacement hose is needing to come with washers in order to fit properly. Since I'm unsure of the diameter I was going to order a universal hose which has adapters for different water inlet sizes. However the hose I was thinking of ordering does not seem to come with washers where my old hose has washers in both ends.

Here is end that connects to the shut off. The plastic inner hose just broke off!!

Are the chances that the end connecting to my water supply shutoff is really a standard 1/2" and I'm just not understanding the way tube/hose diameters are measured?

Are washers optional on these types of fittings or maybe more modern hoses don't need them where older ones did?

Normally I'd just take the bad hose into the store and get this sorted out in person -- but these are not normal times! That leaves me hoping I can just order the right part and get it sent to me.

 

[rjniles]

All you need is a standard toilet supply like the Fluidmaster in your first picture.

3/8 by 7/8 is a standard size..

 

[dj3]

While you down there, might as well replace the shut off valve.

 

[Old Thomas]

Buy a few and return the ones that don’t work.

 

[JoeT]

Thanks for your replies.

Verified it's a 1/2" connector. Sure is confusing to me how the diameter is measured. I even wrapped a string around the threaded outlet and divided by 3.14 and that resulted in slightly larger than 1/2". Eyeballing it with a ruler shows it's greater than 1/2".

 

[dj3]

You sure know your Geometry!

 

[chandler48]

The only thing you didn't show us was the stop valve. We can tell by looking what size you need. You wrapped a string around the OUTSIDE of the fitting. You are looking for the interior dimension.

 

[HotRodx10]

Looks like a typical 3/8" compression fitting to me (the hoses themselves are generally about the same size, so you can tell from that), which is what I would have guessed before I even saw the picture, since that's what the vast majority of them are. A little over 1/2" thread diameter seems about right, too.


Update: Just stepped out to the garage and checked 3/8" compression fitting with the caliper. Results: Outside thread diameter of shutoff fitting .557"; inside thread diameter on supply line .516".


It's a 3/8" compression fitting.