8-117 BLACK BUNA 90D BACK-UP RING

HB90117 is an AS568-117 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 0.799 in (20.29 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.005 in (25.53 mm). In service, this back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The compound resists water, greases and lubricants, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) is known for strong abrasion and tear resistance, low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or strong acids call for a different compound.

Typical settings include construction equipment, fluid power, and hydraulic and pneumatic systems.

HB90117 ships individually. Unit weight is approximately 0.2604 g. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.