Size 154 Buna O-Ring, 70 Durometer, 3-3/4" ID, 3-15/16" OD, 3/32" CS Pack of 100

$ 35.00

  • Made of Buna-nitrile (also called Buna-N) for use with a variety of fluids and hydrocarbons
  • Can be used across a wide temperature range from -30 degrees F (-34 degrees C) to 250 degrees F (121 degrees C)
  • Round in cross-section to provide a seal between cylindrical overlapping surfaces
  • Durometer (hardness) of 70A for resistance to penetration
  • Meets standards defined by Aerospace Standard AS568A


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.