8-160 BLACK BUNA 90D BACK-UP RING

HB90160 is an AS568-160 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 5.237 in (133.02 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 5.443 in (138.25 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

The material holds up against propane and butane, petroleum-based oils, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) offers reliable performance in both static and dynamic service, low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where automotive brake fluid or strong acids are present.

Common environments for this compound include hydraulic and pneumatic systems, automotive, and construction equipment.

This item is sold individually under part number HB90160. Unit weight is approximately 1.538 g and nominal inside diameter is listed as 5 1/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.