568-040 BUNA 70 SQUARE CUT RINGS

SH70040 is an AS568-040 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 2.864 in (72.75 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.004 in (76.3 mm). In service, this square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

As a material, Buna-N (Nitrile) delivers reliable performance in both static and dynamic service, the most widely specified general-purpose sealing elastomer. The material holds up against propane and butane, hydraulic fluids, and petroleum-based oils. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where polar solvents or ketones are present. The profile itself contributes simple lathe-cut manufacture at low tooling cost 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 hydraulic and pneumatic systems, construction equipment, and general industrial maintenance.

Stocked as SH70040 and sold individually. Unit weight is approximately 0.721 g and nominal inside diameter is listed as 2 7/8 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.