568-277 BUNA 70 SQUARE CUT RINGS

APG stocks the SH70277, an AS568-277 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 11.484 in (291.69 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 11.762 in (298.75 mm). A square-cut ring offers greater contact area against the gland wall than an equivalent o-ring.

This material stands up to petroleum-based oils, hydraulic fluids, and water. Buna-N (Nitrile) is specified for reliable performance in both static and dynamic service, the most widely specified general-purpose sealing elastomer. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving ketones or automotive brake fluid call for a different compound. The profile itself contributes greater resistance to extrusion than a round section of the same size and a flat contact band that spreads sealing load across a wider area. 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 hydraulic and pneumatic systems, agricultural equipment, and fluid power.

SH70277 ships individually. Nominal inside diameter is listed as 11 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.