Buna, otherwise known as Nitrile, Buna-N or NBR, is an incredibly versatile synthetic rubber. The unique properties of this material make Buna an ideal material for O-rings, vulcanized or spliced O-rings, gaskets, and other sealing applications for various industries.

Properties of Buna

black o rings on black backgroundBuna offers many unique properties; making it the sealing industry’s most commonly used material. It is a durable, versatile elastomer that’s typically black in color and resistant to various chemicals, including fuel, oil, diluted acids, alkaline, mineral, vegetable oils, and more. Buna is resistant to abrasion, has a low compression set, and has a high tensile strength ranging from 200 to 3000 psi with 300% elongation at break.

Buna is composed of the copolymer acrylonitrile and butadiene and can be formulated to withstand temperatures ranging from -85°F to 275°F. Its hardness durometer ranges from 40-90 and has a hardness rating of 70 Shore A. These features make Buna O-rings and gaskets commonly found in low temperature military equipment and off-road equipment. 

Buna Sealing Device Compatibility

Buna Sealing Device Applications

To determine if Buna is a right O-ring and gasket material for your intended application, it is important to know its compatibility with different chemicals and environments. Buna’s compatibility levels are as follows:

  • Good to excellent. Oil resistance, dynamic resistance, set resistance, tensile strength
  • Good. Abrasion resistance, cold resistance, heat resistance, impermeability
  • Fair to good. Chemical resistance, water steam resistance
  • Fair. Acid resistance, electrical properties, tear resistance, weather resistance
  • Poor. Flame resistance, ozone resistance 

Buna Sealing Device Applications

Buna’s unique properties and features make it the ideal material for sealing devices in many applications across a wide range of industries, including military, medical, automotive, and aerospace. Some common applications for Buna sealing devices include:

  • Fuel tanks
  • Engines
  • Gear boxes
  • Pneumatics
  • Water/hydraulics
  • Military equipment
  • General aerospace assemblies

Buna’s strong chemical resistance makes it suitable for applications where ordinary rubber cannot be used due to its reactivity with fuels and oils. 

Buna O-Rings, Gaskets, and Other Sealing Devices from AZ Seal

Crafting your O-rings, gaskets, and other sealing devices from the correct material ensures that your equipment’s critical components are safe from damage caused by chemicals and extreme environments. Buna is a highly resistant and versatile synthetic rubber that offers many advantages over ordinary rubbers, making it the most commonly used sealing material for several applications across numerous industries. 

AZ Seal is an ideal supplier of sealing device solutions using Buna as well as a wide variety of other materials to ensure that you have the best possible O-rings, gaskets, and other sealing devices for your specific application. To learn more about our products or to get started on your sealing solution, browse our catalog or contact our experts today.