8-450 BLACK BUNA 90D BACK-UP RING

The HB90450 is an AS568-450 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 10.475 in (266.07 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 11.025 in (280.04 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Buna-N (Nitrile) is known for an economical choice for high-volume maintenance programs, strong abrasion and tear resistance. This material stands up to many alcohols, petroleum-based oils, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or ketones call for a different compound.

Maintenance and OEM teams specify it across hydraulic and pneumatic systems, agricultural equipment, and automotive.

Reference part number HB90450 when ordering; the item is sold individually. Unit weight is approximately 0.041 lb and nominal inside diameter is listed as 10 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.