568-205 BUNA 70 SQUARE CUT RINGS

The SH70205 is an AS568-205 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 0.421 in (10.69 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.699 in (17.75 mm). 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 petroleum-based oils, many alcohols, and propane and butane. Buna-N (Nitrile) is specified for the most widely specified general-purpose sealing elastomer and an economical choice for high-volume maintenance programs. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving polar solvents or ozone and direct sunlight call for a different compound. 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.

Common environments for this compound include agricultural equipment, general industrial maintenance, and construction equipment.

SH70205 ships individually. Nominal inside diameter is listed as 7/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.