8-427 BLACK BUNA 90D BACK-UP RING

Part number HB90427 is an AS568-427 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 4.725 in (120.02 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.275 in (133.99 mm). A 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. This material stands up to propane and butane, petroleum-based oils, and water. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It should not be specified for service in automotive brake fluid or polar solvents.

Typical settings include construction equipment, general industrial maintenance, and hydraulic and pneumatic systems.

This item is sold individually under part number HB90427. Unit weight is approximately 8.6398 g. Review your operating media and conditions against this specification before installation.