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Sterling Seal & Supply 232 Buna/Nitrile O-Ring, 70A Durometer, Black, 2-3/4' ID, 3' OD, 1/8' Width (Pack of 5)

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$7.99

$ 2 .99 $2.99

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About this item

  • Made of Buna-nitrile (also called Buna-N) for use with a variety of fluids and hydrocarbons
  • Temperature Range: -35°C (-31°F) to 120°C (248°F); Shelf-life: 15 Years
  • These versatile o-rings perform well in petroleum based oils & fuels, aliphatic hydrocarbons, vegetable oils, silicone oils & greases, ethylene glycol, dilute acids, and water to below 100°C (212°F)
  • Durometer (hardness) of 70A for resistance to penetration
  • O-ring Size meets standards defined by AS568A (b) ID (Nominal): 2-3/4 ID (Nominal): 1/8 CS (Nominal): 3 OD


This O-ring is made of black Buna-nitrile, is round in cross-section, has a durometer of 70A, and is designed for use in a wide variety of sealing applications. Buna-nitrile can have high tensile strength, and abrasion, tear, and compression set resistance. It can be used in temperatures between -30 degrees F (-34 degrees C) to 250 degrees F (121 degrees C), and 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 Buna O-ring has 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. 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 various cylinders. 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 various sizes, and can be ordered based on required nominal inside diameter (ID), outer diameter (OD), and cross-sectional (CS) diameter. These Buna-nitrile O-rings meet standards defined by Aerospace Standard AS568A, which is the Aerospace Size Standard for O-rings.


EngineerInRealLife
Reviewed in the United States on February 23, 2025
Great O-ring, exactly as expected. As a mechanical engineer I routinely find myself needing specific parts. In this case, I designed an O-ring gland for this specific size for an underwater application. O-ring seems good quality and met expected specifications.