568-256 HSN90 DURO ORINGS

Part number HSN90256 is an AS568-256 green HNBR (Hydrogenated Nitrile) 90 Shore A O-Ring measuring an inside diameter of 5.734 in (145.64 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.012 in (152.7 mm). An o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

This material stands up to heat and oxidation, ozone and weathering, and petroleum oils and fuels. That behavior comes from the compound itself: HNBR (Hydrogenated Nitrile) is known for long service life in refrigerant and oilfield duty, strong resistance to rapid gas decompression. Service temperature is rated from -40°F (-40°C) through 325°F (162.8°C). Applications involving ketones or esters call for a different compound.

It sees regular use in oilfield and downhole equipment, heavy-duty powertrain, and commercial refrigeration.

Reference part number HSN90256 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 3/4 inch. Check the compound against your process media, pressure and temperature before committing to a design.