How do I measure an O Ring?

oringHow do I measure an O Ring? This is a question that we get asked frequently at Rhondama.

O rings are actually really easy to measure. First of all you need to measure the internal diameter (ID). You then need to measure what we call the width or cross section (C/S) of the o ring. The diagram to the right illustrates exactly where these dimensions are to be found. Once you have these measurements you then need to decide if the sizes recorded best fit metric or imperial standards. This is all well and good but more often than not o rings will lose there shape over time, so taking an accurate measurement can be close to impossible. When this is the case all you need to do is measure the width of the groove or shaft where the o ring is to be seated as well as the depth of the same groove. With these measurements we will be able to calculate the size of o ring your are looking for. Should you require any assistance with o ring sizes please just get in touch and our expert sales team who will be happy to assist you further.

We also sell a range of tools to help you measure o rings. These tools include measurement cones, digital callipers and pick sets.

Nitrile O Rings   –  Viton O Rings   –   EPDM O Rings   –   Silicone O Rings

Size charts for metric and imperial measurements can be found here