Buna 70-350-Black-Pk5

This o-ring is supplied in AS568-350 black Buna-N (Nitrile) 70 Shore A with an inside diameter of 4.6 in (116.84 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.02 in (127.51 mm), catalogued under part number SB-H70350-5. It compresses into its gland to block fluid or gas migration across a joint. Supplementary detail from the product record: 5IDX4.625"ODX.1875"CS.

The compound resists water, greases and lubricants, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer and low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in ozone and direct sunlight or polar solvents.

It sees regular use in construction equipment, fluid power, and general industrial maintenance.

Stocked as SB-H70350-5 and sold by the bag. Nominal inside diameter is listed as 4 5/8 inch. Review your operating media and conditions against this specification before installation. 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.