8-044 BLACK BUNA 90D BACK-UP RING

Part number HB90044 is an AS568-044 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 3.739 in (94.97 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.879 in (98.53 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is valued for an economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. The compound resists many alcohols, petroleum-based oils, and propane and butane. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to ozone and direct sunlight or strong acids will shorten service life.

Maintenance and OEM teams specify it across general industrial maintenance, hydraulic and pneumatic systems, and automotive.

Reference part number HB90044 when ordering; the item is sold individually. Unit weight is approximately 0.644 g and nominal inside diameter is listed as 3 3/4 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.