Nitrile Rubber | NBR | Buna-N | Seal & Design

NBR Nitrile       ASTM D 2000, SAE J200 Type/Class: BF, BG, BK, CH

General Characteristics

Nitrile rubber is the general term for acrylonitrile butadiene terpolymer. The acrylonitrile content of nitrile sealing compounds varies considerably (18% to 50%) and influences the physical properties of the finished material.

The higher the acrylonitrile content, the better the resistance to oil and fuel. At the same time, elasticity and resistance to compression set is adversely affected. In view of these opposing realities, a compromise is often drawn, and a medium acrylonitrile content selected. Nitrile has good mechanical properties when compared with other elastomers and high wear resistance.

AKAs: Buna
Varieties: Low Temp. Nitrile, Hydrogenated NBR (HNBR)

Temperature Properties

Heat Heat Resistance Up to approximately 212°F (100°C)
with shorter life at 250°F (121°C)
Cold Cold Flexibility Depending on individual compound,
between -30°F (–34°C) and -70°F (-57°C)


Chemical Resistance Chemical Resistance
  • Aliphatic hydrocarbons (propane, butane, petroleum oil, mineral oil and grease, diesel fuel, fuel oils) vegetable and mineral oils and greases
  • HFA, HFB, and HFC fluids
  • Dilute acids, alkali and salt solutions at low temps.
  • Water (special compounds up to 212°F (100°C)
Not compatible NOT compatible
  • Fuels of high aromatic content (for flex fuels a special compound must be used)
  • Aromatic hydrocarbons (benzene)
  • Chlorinated hydrocarbons (trichloroethylene)
  • Polar solvents (ketones, esters, ethers, acetones)
  • Strong acids
  • Glycol based brake fluids
  • Ozone, weather, and atmospheric aging

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