-391 BLACK BUNA 50D O-RING

The H50391 is an AS568-391 black Buna-N (Nitrile) 50 Shore A O-Ring built to an inside diameter of 21.953 in (557.61 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 22.373 in (568.27 mm). This o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.

The compound resists many alcohols, petroleum-based oils, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) offers the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

You will find this material specified across general industrial maintenance, construction equipment, and hydraulic and pneumatic systems.

Stocked as H50391 and sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.