8-392 BLACK BUNA 90D BACK-UP RING

Ordered as HB90392, this is an AS568-392 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 22.94 in (582.68 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 23.36 in (593.34 mm). The back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

This material stands up to hydraulic fluids, greases and lubricants, and many alcohols. Buna-N (Nitrile) is widely chosen for strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with ozone and direct sunlight or automotive brake fluid.

You will find this material specified across construction equipment, general industrial maintenance, and fluid power.

HB90392 ships individually. Unit weight is approximately 19.08 g and nominal inside diameter is listed as 23 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.