8-330 BLACK BUNA 90D BACK-UP RING

Part number HB90330 is an AS568-330 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 2.1 in (53.34 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.52 in (64.01 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

It resists many alcohols, petroleum-based oils, and greases and lubricants. 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. Verify compatibility before use with ozone and direct sunlight or automotive brake fluid.

Typical settings include general industrial maintenance, fluid power, and hydraulic and pneumatic systems.

This item is sold individually under part number HB90330. Unit weight is approximately 1.9999 g and nominal inside diameter is listed as 2 1/8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.