568-351 HSN90 DURO ORINGS

HSN90351 is an AS568-351 green HNBR (Hydrogenated Nitrile) 90 Shore A O-Ring with an inside diameter of 4.725 in (120.02 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.145 in (130.68 mm). In service, this o-ring compresses into its gland to block fluid or gas migration across a joint.

HNBR (Hydrogenated Nitrile) is known for improved ozone and weathering resistance over standard nitrile, excellent abrasion and tear strength. The compound resists modern refrigerants, petroleum oils and fuels, and ozone and weathering. The material carries a published service range of -40°F (-40°C) to 325°F (162.8°C). Exposure to esters or strong oxidizing acids will shorten service life.

Maintenance and OEM teams specify it across commercial refrigeration, engine timing systems, and oilfield and downhole equipment.

This item is sold individually under part number HSN90351. Nominal inside diameter is listed as 4 3/4 inch. 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.