8-210 BLACK BUNA 90D BACK-UP RING

Ordered as HB90210, this is an AS568-210 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 0.734 in (18.64 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.012 in (25.7 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.

Buna-N (Nitrile) is specified here for low compression set under sustained load and most widely specified general-purpose sealing elastomer. The material holds up against petroleum-based oils, greases and lubricants, and hydraulic fluids. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Verify compatibility before use with ketones or strong acids.

Typical settings include agricultural equipment, general industrial maintenance, and automotive.

This item is sold individually under part number HB90210. Unit weight is approximately 0.324 g and nominal inside diameter is listed as 3/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.