-255 BLACK BUNA 50D O-RING

APG stocks the H50255, an AS568-255 black Buna-N (Nitrile) 50 Shore A O-Ring built to an inside diameter of 5.609 in (142.47 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.887 in (149.53 mm). An o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.

Buna-N (Nitrile) is specified here for economical choice for high-volume maintenance programs and low compression set under sustained load. It resists water, propane and butane, and greases and lubricants. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Exposure to ozone and direct sunlight or polar solvents will shorten service life.

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

Reference part number H50255 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 5/8 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.