8-037 BLACK BUNA 90D BACK-UP RING

The HB90037 is an AS568-037 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 2.489 in (63.22 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.629 in (66.78 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

It resists propane and butane, hydraulic fluids, and greases and lubricants. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for reliable performance in both static and dynamic service, strong abrasion and tear resistance. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in polar solvents or ozone and direct sunlight.

You will find this material specified across fluid power, automotive, and construction equipment.

Order part number HB90037, sold individually. Unit weight is approximately 0.449 g and nominal inside diameter is listed as 2 1/2 inch. 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.