8-283 BLACK BUNA 90D BACK-UP RING

HB90283 is an AS568-283 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 16.955 in (430.66 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 17.233 in (437.72 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

It resists greases and lubricants, petroleum-based oils, and propane and butane. Buna-N (Nitrile) is specified for strong abrasion and tear resistance, reliable performance in both static and dynamic service. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

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

Reference part number HB90283 when ordering; the item is sold individually. Unit weight is approximately 6.665 g. 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.