8-259 BLACK BUNA 90D BACK-UP RING

Part number HB90259 is an AS568-259 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 6.234 in (158.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.512 in (165.4 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, Buna-N (Nitrile) is widely chosen for an economical choice for high-volume maintenance programs and the most widely specified general-purpose sealing elastomer. The material holds up against many alcohols, petroleum-based oils, 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.

It sees regular use in hydraulic and pneumatic systems, automotive, and fluid power.

This item is sold individually under part number HB90259. Unit weight is approximately 2.344 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.