8-367 BLACK BUNA 90D BACK-UP RING

Ordered as HB90367, this is an AS568-367 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 7.475 in (189.87 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 7.895 in (200.53 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

It resists petroleum-based oils, many alcohols, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) delivers low compression set under sustained load and the most widely specified general-purpose sealing elastomer. 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 automotive, fluid power, and general industrial maintenance.

HB90367 ships individually. Unit weight is approximately 6.304 g. Review your operating media and conditions against this specification before installation.