8-008 BLACK BUNA 90D BACK-UP RING

HB90008 is an AS568-008 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 0.176 in (4.47 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.316 in (8.03 mm). In service, this back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Buna-N (Nitrile) is specified here for economical choice for high-volume maintenance programs and low compression set under sustained load. The material holds up against water, propane and butane, and many alcohols. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving ketones or polar solvents call for a different compound.

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

Reference part number HB90008 when ordering; the item is sold individually. Unit weight is approximately 0.0489 g and nominal inside diameter is listed as 3/16 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.