8-238 BLACK BUNA 90D BACK-UP RING

The HB90238 is an AS568-238 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 3.484 in (88.49 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.762 in (95.55 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

This material stands up to many alcohols, water, and petroleum-based oils. Buna-N (Nitrile) delivers low compression set under sustained load and the most widely specified general-purpose sealing elastomer. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C).

Common environments for this compound include fluid power, construction equipment, and automotive.

This item is sold individually under part number HB90238. Unit weight is approximately 1.2944 g and nominal inside diameter is listed as 3 1/2 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.