8-273 BLACK BUNA 90D BACK-UP RING

HB90273 is an AS568-273 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 9.734 in (247.24 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 10.012 in (254.3 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

Buna-N (Nitrile) is specified here for most widely specified general-purpose sealing elastomer and low compression set under sustained load. This material stands up to petroleum-based oils, many alcohols, and greases and lubricants. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or ozone and direct sunlight call for a different compound.

Typical settings include agricultural equipment, fluid power, and general industrial maintenance.

Reference part number HB90273 when ordering; the item is sold individually. Unit weight is approximately 3.6074 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.