8-050 BLACK BUNA 90D BACK-UP RING

The HB90050 is an AS568-050 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 5.239 in (133.07 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 5.379 in (136.63 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 strong abrasion and tear resistance, reliable performance in both static and dynamic service. The compound resists greases and lubricants, many alcohols, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in strong acids or automotive brake fluid.

Typical settings include construction equipment, automotive, and fluid power.

Order part number HB90050, sold individually. Unit weight is approximately 0.907 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.