568-258 BUNA 70 SQUARE CUT RINGS

SH70258 is an AS568-258 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring with an inside diameter of 5.984 in (151.99 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.262 in (159.05 mm). In service, this square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

The compound resists greases and lubricants, water, and hydraulic fluids. Buna-N (Nitrile) is valued for low compression set under sustained load, reliable performance in both static and dynamic service. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. The profile itself contributes a flat contact band that spreads sealing load across a wider area 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 general industrial maintenance, automotive, and fluid power.

Stocked as SH70258 and sold individually. Unit weight is approximately 7.0456 g. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.