8-374 BLACK BUNA 90D BACK-UP RING

Ordered as HB90374, this is an AS568-374 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 9.225 in (234.32 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 9.645 in (244.98 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, Buna-N (Nitrile) delivers the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Expect good resistance to petroleum-based oils, many alcohols, and greases and lubricants. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). It should not be specified for service in automotive brake fluid or polar solvents.

You will find this material specified across automotive, agricultural equipment, and hydraulic and pneumatic systems.

Reference part number HB90374 when ordering; the item is sold individually. Unit weight is approximately 7.8412 g and nominal inside diameter is listed as 9 1/4 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.