O-Rings Without the “O”

A common question that comes up is whether or not o-rings can be used in grooves that are not circular. At first, it sounds like a silly questions, why would it be called an o-ring if it can be used for things that are not “o” shaped? We looked into it, and the answer is surprisingly that you can do just that!

While the o-ring can indeed be used in unorthodox situations, it’s not always the most ideal choice but before we talk about the alternative, let us dive into the not so luctus concept of using an o-ring for non-circular grooves.

When determining if an o-ring is able to be safely installed into a non-circular groove, you must pay attention to the stress the curves add to the o-ring. Overstressing the ring could cause it to snap. You must also be aware of any creasing on the corners, which could lead to leaks due to spaces between the ring and the surface.

So while the o-ring can be used in a non-circular groove, there are of course risks involved as it was not intentionally designed to be used in that fashion. If you’re concerned about using an o-ring in this way, then you have an alternative and more practical option.

Enter, the o-seal. The advantage of the o-seal is that it’s a custom seal built to the dimensions of the groove. This will eliminate the chance for leakage or an incorrect installation of an 0-ring. The o-seal is perfect for situations where gaskets and o-rings are not applicable.

But, that’s just a very basic overview. If you’re interested in learning more about o-rings and fluid seals, then we recommend checking out Gallagher Fluid Seal’s guide on them. Gallagher has an entire list of guides they’ve written about the fluid seal industry.