309 – Acrylonitrile Butadiene Rubber, Nitrile or Buna N (NBR)

ASTM D-2000 classification: BF, BG, BJ, BK, CH


Temperature Range:

-35°C to +120°C (-30°F to +250°F)



Acrylonitrile or Nitrile as it’s more commonly referred to is a copolymer of Acrylonitrile and Butadiene. The Nitrile content varies in commercial products from 18% to 50%, the higher the Nitrile content the better the resistance to petroleum oils and hydrocarbon fuels, but low temperature flexibility decreases.

As Nitrile has an excellent resistance to petroleum products, and an ability to be compounded for service over a wide temperature range, Nitrile is the most widely used elastomer in the seal industry today. Nitrile compounds are superior to most elastomers with regard to compression set, tear, and abrasion resistance but have limited resistance to ozone, sunlight, or weather. To obtain good resistance to lower temperatures, it is often necessary to sacrifice some high temperature resistance. Nitrile should not be kept near electric motors or other ozone generating equipment and should not be kept in direct sunlight.



Nitrile is the standard material for hydraulics and pneumatics; it has good resistance to oil-based hydraulic fluids, fats, animal and vegetable oils, flame retardant liquids (HFA, HFB, HFC), grease, water, and air. Special low-temperature compounds are available for mineral oil-based fluids. By hydrogenation, carboxylic acid addition, or PVC blending, the Nitrile polymer can meet a more specified range of physical or chemical requirements.


EMI ReferenceSpecificationHardness IRHDSGTensile Strength (MPa)Elongation at Break %Colour
309 -ABA40BS2751:BA4040°1.27600Black
309 - A502Commercial50°1.44250Black
309 - A501Commercial50°1.275350Black
309 - ABA50BS2751:BA5050°1.28450Black
309 - A601Commercial60°1.454200Black
309 - A608High Grade 60°1.1611400Black
309 - A604Food Quality 60°1.3211500White
309 - ABA60BS2751:BA6060°1.3213500Black
309 - A658High Grade 65°1.457250Black
309 - A656BFood Quality65°1.48500Blue
309 - A656WFood Quality65°1.48500White
309 - A701Commercial70°1.484250Black
309 - A708High Grade 70°1.4910330Black
309 - A707Insertion/Reinforced70°1.48--Black
309 - ABA70BS2751:BA7070°1.215350Black
309 - ABA80BS2751:BA8080°1.313325Black

Full data sheets for all grades are available on request.

* The information above is supplied in good faith and believed to be correct. This information is supplied upon the condition that persons receiving this will make their own determination as to its suitability for their purposes prior to use. EMI makes no representations or warranties, either expressed or implied with respect to the information or the product to which this information refers.