8-355 BLACK BUNA 90D BACK-UP RING

Part number HB90355 is an AS568-355 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 5.225 in (132.72 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.645 in (143.38 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is specified here for strong abrasion and tear resistance, economical choice for high-volume maintenance programs. The material holds up against petroleum-based oils, water, and greases and lubricants. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with strong acids or automotive brake fluid.

It sees regular use in construction equipment, automotive, and agricultural equipment.

Stocked as HB90355 and sold individually. Unit weight is approximately 4.6316 g. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.