8-350 BLACK BUNA 90D BACK-UP RING

Part number HB90350 is an AS568-350 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 4.6 in (116.84 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.02 in (127.51 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is known for an economical choice for high-volume maintenance programs and low compression set under sustained load. The compound resists propane and butane, petroleum-based oils, and hydraulic fluids. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

Common environments for this compound include automotive, construction equipment, and fluid power.

Order part number HB90350, sold individually. Unit weight is approximately 4.081 g and nominal inside diameter is listed as 4 5/8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.