Buna-N (Nitrile) 70 Durometer O-ring cord stock is made from a general-purpose synthetic rubber copolymer of butadiene and acrylonitrile. It is a highly versatile and economical material widely used for creating custom-sized static seals and gaskets by cutting and bonding the cord to length. Buna 70 provides excellent resistance to petroleum-based oils, hydraulic fluids, and water, along with good mechanical properties like tear and abrasion resistance, making it the industry standard for general industrial sealing.

General industrial sealing, hydraulic and pneumatic systems, automotive fuel and oil handling, water-based applications, manufacturing machinery, grease and lubricant environments, and custom-size static gasket fabrication.

Ozone, weathering, sunlight, UV exposure, automotive brake fluids, ketones, esters, strong acids, chlorinated hydrocarbons, and high-temperature steam applications.

Buna 70 Limitations

• Poor resistance to ozone, sunlight, and outdoor weathering.
• Degrades rapidly when exposed to polar solvents like acetone or MEK.
• Limited maximum temperature capability compared to fluorocarbon elastomers.
• Not suitable for dynamic applications if the bonded joint faces high tensile stress.

-40 to 250°F (-40 to 121°C)

Nitrile Cord Stock, NBR 70 Cord, Buna-N Cord, Acrylonitrile Butadiene, Perbunan®.