8-457 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-457 black Buna-N (Nitrile) 90 Shore A with an inside diameter of 13.975 in (354.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 14.525 in (368.94 mm), catalogued under part number HB90457. It bridges the extrusion gap so the primary seal holds its shape under load.

The material holds up against propane and butane, hydraulic fluids, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C).

You will find this material specified across automotive, fluid power, and hydraulic and pneumatic systems.

This item is sold individually under part number HB90457. Unit weight is approximately 24.28 g. 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.