-904 BLACK BUNA 90D O-RING

H90904 is an AS568-904 black Buna-N (Nitrile) 90 Shore A O-Ring built to an inside diameter of 0.351 in (8.92 mm), a cross section of 0.072 in (1.83 mm), and an outside diameter of 0.495 in (12.57 mm). In service, this o-ring seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.

Buna-N (Nitrile) is specified here for low compression set under sustained load and most widely specified general-purpose sealing elastomer. It resists propane and butane, petroleum-based oils, and many alcohols. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to polar solvents or automotive brake fluid will shorten service life.

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

H90904 ships individually. Unit weight is approximately 0.1253 g and nominal inside diameter is listed as 1/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.