NBR O-Rings

Most of the O-Rings are elastomer-made. Elastomer refers to the elasticity of rubbers that change shape when subjected to force and return to their original shape as soon as the force ceases. The base of these elastomers is rubber. This can be “natural” when it comes from plantations or “synthetic” when it comes from the chemical industry. Nowadays, the second option is usually the one applied for the production of O-rings.

One of the most commonly used synthetic rubbers for the manufacture of O-Rings is NBR, which chemical name of the basic polymer is: Acrylonitrile-butadiene rubber (DIN ISO 1629: NBR / ASTM D 1418: NBR).

NBR O-rings offer good resistance to:

• Oils and greases based on mineral oils
• Halifatic Hydrocarbon
• Vegetable and animal oils and greases
• Hydraulic oils (H, H-L, H-LP)
• Hydraulic fluids (HFA, HFB, HFC)
• Silicone oils and silicone greases
• Water (maximum at 80 °C)

But are not advised in contact with:

• Fuels with a high aromatic content
• Aromatic hydrocarbons
• Chlorinated hydrocarbons
• Non-polar solvents
• Glycol-based brake fluids
• Ozone, weathering, ageing

In the o-rings, acrylonitrile-butadiene rubber (NBR) is the most common material due to its good mechanical properties, its high resistance to abrasion, its low gas permeability and high resistance to oils and greases based on oils minerals. NBR is a copolymer of butadiene and acrylonitrile. Depending on the application, the content of acrylonitrile can vary between 18% and 50%.

Go to Brochures to download complete information about our O-Rings..