8-246 BLACK BUNA 90D BACK-UP RING

The HB90246 is an AS568-246 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 4.484 in (113.89 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.762 in (120.95 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Expect good resistance to petroleum-based oils, greases and lubricants, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) offers the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C).

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

Order part number HB90246, sold individually. Unit weight is approximately 1.6479 g and nominal inside diameter is listed as 4 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.