Small O-Rings, Buna Nitrile Rubber, 70 Shore A, for Industrial Use (Pack of 1000)

Nitrile, also known as Buna N, is a copolymer of butadiene and acrylonitrile that is widely used in the seal industry due to its excellent resistance to petroleum products. The acrylonitrile content in commercial products can vary from 18% to 48%, with higher nitrile content leading to increased resistance to petroleum-based oils and hydrocarbon fuels, but decreased low-temperature flexibility.

One of the primary advantages of nitrile is its ability to be compounded for service over a wide temperature range, from -65 to +275 degrees Fahrenheit (-54 to +135 degrees Celsius). This makes it the most widely used elastomer in the seal industry, particularly for military rubber specifications that require fuel and oil-resistant MS and AN O-rings.

It is important to note, however, that to obtain good low-temperature resistance with nitrile compounding, it is often necessary to sacrifice some high-temperature fuel and oil resistance. Nonetheless, nitrile compounds are superior to most elastomers in terms of compression set or cold flow, tear, and abrasion resistance.

Inherently, nitrile compounds possess good resistance to ozone, sunlight, and weather, but this can be further improved through compounding. However, since ozone and weather resistance are not always built-in, seals made from nitrile bases should not be stored near electric motors or other equipment that may generate ozone, or in direct sunlight.

Nitrile is compatible with a wide range of aliphatic hydrocarbons, including propane, butane, petroleum oil, mineral oils and greases, diesel fuel, and fuel oil. However, it is not compatible with products that have a high aromatic content, such as benzene, or with chlorinated hydrocarbons like trichloroethylene.

The excellent mechanical properties and high wear resistance of Buna N or nitrile make it a popular choice for a variety of applications, including:

1. Oil-resistant applications of all types
2. Low-temperature military uses
3. Off-road equipment
4. Automotive, marine, and aircraft fuel systems

With a durometer of 70, nitrile is suitable for use across a wide temperature range, from -30 degrees Fahrenheit to 250 degrees Fahrenheit, while providing good to excellent resistance to many petroleum oils, greases, hydraulic fluids, alcohol, mineral oil, and grease.

In summary, the versatility, resistance to petroleum products, and mechanical properties of Buna N or nitrile make it a widely used and preferred elastomer in the seal industry, finding applications in a diverse range of industries and environments.

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