This quad-ring is made of black Buna-nitrile (also called Buna-N), has a durometer (hardness) of 70A, and can be used in a wide variety of static and dynamic sealing applications.

This Buna-nitrile quad-ring has high tensile strength, and abrasion, tear, and compression set resistance. Buna-nitrile is acceptable for temperature applications between -30 degrees F (-34 degrees C) to 250 degrees F (121 degrees C). It is compatible for use with petroleum, HFA, HFB, and HFC fluids, vegetable oil, and other aliphatic hydrocarbons. Buna-nitrile is vulnerable to ozone, sunlight, and weathering and should therefore not be used in ozone-generating electric motors, welding equipment, or in applications with direct exposure to UV light.

Buna-nitrile quad-rings have a shore durometer of 70A. Shore durometer is the hardness of a material, and its resistance to permanent indentation. A higher durometer value indicates greater resistance to indentation on a scale of 0 to 100, with 100 indicating no indentation.

Quad-rings, also called X-rings, provide a pressure and fluid seal between overlapping surfaces in static and dynamic sealing applications, and are commonly used in engines, faucets, flanges, valves, and various cylinders. They have a four-lobe design, to provide two contact points, which results in less friction, twisting and leakage. Quad-rings are available in a number of different sizes, and can be ordered based on required nominal inside diameter (ID), outer diameter (OD), and cross-sectional (CS) diameter.

Buna quad-rings meet standards defined by Aerospace Standard AS568A, Aerospace Size Standard for O-rings.