As with all technical products, there is no universal solution for O‑rings for all applications. The material as well as the dimensions and assembly of the O‑rings must be adapted to the respective overall system and the given influences. If an assembly is exposed to external weather conditions, the material EPDM (ethylene propylene diene rubber) has become established.
Since EPDM is highly resistant to ozone and ageing and also has good resistance to cold temperatures, the material is predestined for such areas. However, EPDM has no resistance to mineral oil-based media and swells strongly under their influence. In this case, NBR (acrylonitrile-butadiene rubber) is the ideal choice, as this rubber is highly resistant to greases and oils based on mineral oil.