Buna 70-265-Black-Pk5

APG stocks the SB-H70265-5, an AS568-265 black Buna-N (Nitrile) 70 Shore A O-Ring with an inside diameter of 7.734 in (196.44 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 8.012 in (203.5 mm). An o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load. The catalog record notes: 8IDX7.75"ODX.125"CS.

This material stands up to greases and lubricants, many alcohols, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) offers low compression set under sustained load and the most widely specified general-purpose sealing elastomer. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to ozone and direct sunlight or ketones will shorten service life.

Common environments for this compound include hydraulic and pneumatic systems, agricultural equipment, and fluid power.

This item is sold by the bag under part number SB-H70265-5. Nominal inside diameter is listed as 7 3/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.