8-031 BLACK BUNA 90D BACK-UP RING

Part number HB90031 is an AS568-031 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 1.739 in (44.17 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 1.879 in (47.73 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Buna-N (Nitrile) is widely chosen for reliable performance in both static and dynamic service, low compression set under sustained load. This material stands up to greases and lubricants, petroleum-based oils, and hydraulic fluids. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Exposure to strong acids or automotive brake fluid will shorten service life.

Common environments for this compound include agricultural equipment, general industrial maintenance, and construction equipment.

Stocked as HB90031 and sold individually. Unit weight is approximately 0.315 g and nominal inside diameter is listed as 1 3/4 inch. Review your operating media and conditions against this specification before installation.