8-449 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-449 black Buna-N (Nitrile) 90 Shore A built to an inside diameter of 9.975 in (253.37 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 10.525 in (267.34 mm), catalogued under part number HB90449. It allows a standard o-ring to operate at higher pressures than it could unsupported.

Buna-N (Nitrile) is known for low compression set under sustained load and the most widely specified general-purpose sealing elastomer. The compound resists petroleum-based oils, hydraulic fluids, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Exposure to ketones or polar solvents will shorten service life.

Common environments for this compound include construction equipment, general industrial maintenance, and hydraulic and pneumatic systems.

HB90449 ships individually. Unit weight is approximately 17.479 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.