Acrylonitrile-butadiene rubber (NBR) is the material name for nitrile rubber. This material is very good for seals due to its make up.
Nitrile rubber can tolerate short-term dry running of the sealing lip. The operating temperature range without failure of nitrile rubber is –40 to +100 °C. SKF also offers a special nitrile rubber compound with a temperature range between –55 and +110 °C.