8-026 BLACK BUNA 90D BACK-UP RING

Part number HB90026 is an AS568-026 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 1.239 in (31.47 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 1.379 in (35.03 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, Buna-N (Nitrile) is valued for strong abrasion and tear resistance, low compression set under sustained load. Expect good resistance to many alcohols, petroleum-based oils, and greases and lubricants. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service.

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

Order part number HB90026, sold individually. Unit weight is approximately 0.2497 g and nominal inside diameter is listed as 1 1/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.