8-336 BLACK BUNA 90D BACK-UP RING

The HB90336 is an AS568-336 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 2.85 in (72.39 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 3.27 in (83.06 mm). This back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

Buna-N (Nitrile) is specified here for low compression set under sustained load and most widely specified general-purpose sealing elastomer. The material holds up against water, greases and lubricants, and propane and butane. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in polar solvents or ketones.

Typical settings include construction equipment, general industrial maintenance, and agricultural equipment.

This item is sold individually under part number HB90336. Unit weight is approximately 2.5534 g and nominal inside diameter is listed as 2 7/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.