8.4MM CS X 289.5MM ID BLACK BUNA 70D

This o-ring is supplied in black Buna-N (Nitrile) 70 Shore A supplied with an inside diameter of 289.5 mm (11.398 in), a cross section of 8.4 mm (0.331 in), and an outside diameter of 306.3 mm (12.06 in), catalogued under part number H8.4X289.5. It provides a reliable static or dynamic seal by deforming into its gland under assembly load. The catalog record notes: Metric O-RING, JIS P290.

The compound resists greases and lubricants, many alcohols, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) offers low compression set under sustained load and the most widely specified general-purpose sealing elastomer. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Applications involving polar solvents or strong acids call for a different compound.

Maintenance and OEM teams specify it across construction equipment, general industrial maintenance, and agricultural equipment.

Stocked as H8.4X289.5 and sold individually. Unit weight is approximately 63.15 g. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.