8-357 BLACK BUNA 90D BACK-UP RING

Part number HB90357 is an AS568-357 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 5.475 in (139.07 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.895 in (149.73 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is specified here for strong abrasion and tear resistance, low compression set under sustained load. It resists greases and lubricants, many alcohols, and water. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C).

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

Stocked as HB90357 and sold individually. Unit weight is approximately 4.7578 g and nominal inside diameter is listed as 5 1/2 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.