This metric O-ring is made of Buna-nitrile (also called Buna-N), round in cross-section, has a durometer of 90A, and is designed for use in a wide variety of sealing applications.
Buna-nitrile can have high tensile strength, resistance to abrasion, tear, and compression set resistance. It 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, alcohol, acids, and aliphatic hydrocarbons. Buna-nitrile is vulnerable to acetone, ethers, esters, ozone, sunlight, and weathering, and should therefore not be used in ozone-generating electric motors, welding equipment, or in applications with exposure to UV light.
This O-ring has a shore durometer of 90A. 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.
O-rings commonly provide a pressure and fluid seal between cylindrically shaped, overlapping mating surfaces and are commonly seen in engines, faucets, flanges, valves and cylinders of various sorts. They are circular in shape, with a round cross section and a hole in the center, similar to a doughnut. O-rings are available in a number of sizes, and can be ordered based on required inside diameter (ID), outside diameter (OD), and cross-sectional (CS) diameter.