8-363 BLACK BUNA 90D BACK-UP RING

HB90363 is an AS568-363 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 6.475 in (164.47 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 6.895 in (175.13 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Buna-N (Nitrile) delivers strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. The material holds up against propane and butane, hydraulic fluids, and water. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in ketones or automotive brake fluid.

It sees regular use in fluid power, automotive, and construction equipment.

HB90363 ships individually. Unit weight is approximately 5.5087 g. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.