Forum Discussion

tarnold's avatar
tarnold
Explorer
Nov 10, 2015

O ring measure

In measuring for a new Oring, do you measure from the inside, outside or middle? I'm looking at my water filter and need a new ring. The ring is about 4" but 1/8" thick. So that would be about .25 difference between inside and outside. I know smaller would stretch but just wondering.
  • Go on to the website of any online water filter store. They all sell o-rings. Most of the time, when you order a single o-ring by size you get a bag of assorted o-rings. In the bag will be an o-ring that will fit your water filter. It is just as cheap to buy the o-ring "kits" as it is to buy a single o-ring and then you can give the rest of the bag to someone who uses a different brand filter than you. I currently have 5 or 6 unopened bags of o-rings in my garage. This way I have o-rings for my well filters and my trailer filters.
    Randy
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    WyoTraveler wrote:
    If you look on the internet you will see they list all 3 dimensions. I.D., O.D.& dia of the material i.e. O.D minus I.D.


    X2, and McMaster Carr has all this info. Measure the old one with calipers.
  • all the work, but you need a good measurement of the thickness. And a good supplier.
  • If you look on the internet you will see they list all 3 dimensions. I.D., O.D.& dia of the material i.e. O.D minus I.D.
  • midnightsadie wrote:
    X2 to the store lowes or ace .


    Real hardware stores are not as common as the Big Box Stores and Chain Stores.
    Fortunately they usually have what you need.
  • 1. The size of a used o-ring will be different than a new one.
    2. I just take the assembly to the store and test fit.
  • I have always just taken in my old o-ring to Home Depot and found a perfect match...
    But, these guys have every 0-ring under the sun listed by filter name and manufacturer....

    O-Rings>>>HERE
  • Smaller may stretch, but then it might be too thin to seal properly. The O-ring should have its size listed: OD, ID, and/or thickness. IOW you might find ID and thickness, or OD and thickness.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,188 PostsLatest Activity: Jan 19, 2025