This specification covers a butadiene-acrylonitrile (NBR) rubber in the form of molded rings. These rings have been used typically for sealing at temperatures as low as -55 degrees C (-67 degrees F) where resistance to hot petroleum-base lubricating oil is required, but usage is not limited to such applications.
SAE AMS7274H-1991 history
2020SAE AMS7274K-2020 Rubber: Acrylonitrile-Butadiene (NBR) Engine Oil Resistance, 65 to 75 Hardness, for Seals in Aircraft Engine Oil Systems
2014SAE AMS7274J-2014 Rubber, Butadiene-Acrylonitrile (NBR), 65 to 75 Hardness, For Elastomeric Seals in Aircraft Engine Oil Systems