ASTM D1414 (D 1414) covers multiple properties of O-Rings. Part of the specification includes tension testing for determining the breaking force, tensile strength, and ultimate elongation of an o-ring ...

For more than 60 years, engineers specifying seals and customers using them have accepted the arbitrary rule that the maximum amount O-rings will swell in most applications is a 25% change in volume.

Sometimes it IS simply a matter of matching the damaged O-ring to a new O-ring from the box of assorted SAE O-rings you bought at the local auto parts store. Problem solved. But what if you can’t find ...