Properties of Buna

Buna 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

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