-139 BLACK BUNA 50D O-RING

H50139 is an AS568-139 black Buna-N (Nitrile) 50 Shore A O-Ring built to an inside diameter of 2.175 in (55.25 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.381 in (60.48 mm). In service, this o-ring remains the most cost-effective sealing element available for pressurized assemblies.

The compound resists propane and butane, petroleum-based oils, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for low compression set under sustained load, strong abrasion and tear resistance. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Verify compatibility before use with automotive brake fluid or ozone and direct sunlight.

You will find this material specified across construction equipment, fluid power, and hydraulic and pneumatic systems.

Order part number H50139, sold individually. Unit weight is approximately 0.0013 g and nominal inside diameter is listed as 2 3/16 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.