568-255 HSN90 DURO ORINGS

Ordered as HSN90255, this is an AS568-255 green HNBR (Hydrogenated Nitrile) 90 Shore A O-Ring measuring 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). The o-ring provides a reliable static or dynamic seal by deforming into its gland under assembly load.

This material stands up to ozone and weathering, modern refrigerants, and heat and oxidation. That behavior comes from the compound itself: HNBR (Hydrogenated Nitrile) is specified for improved ozone and weathering resistance over standard nitrile, long service life in refrigerant and oilfield duty. Published continuous service range is -40°F (-40°C) to 325°F (162.8°C). Applications involving strong oxidizing acids or ketones call for a different compound.

You will find this material specified across commercial refrigeration, engine timing systems, and automotive air conditioning.

Stocked as HSN90255 and sold individually. Nominal inside diameter is listed as 5 5/8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.