568-351 BUNA 70 SQUARE CUT RINGS

SH70351 is an AS568-351 black Buna-N (Nitrile) 70 Shore A Square-Cut 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 square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

Expect good resistance to water, propane and butane, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer and an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). The profile itself contributes a rectangular section that will not roll in the groove and greater resistance to extrusion than a round section of the same size. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

You will find this material specified across fluid power, construction equipment, and automotive.

Order part number SH70351, sold individually. Unit weight is approximately 10.931 g and nominal inside diameter is listed as 4 3/4 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.