568-391 BUNA 70 SQUARE CUT RINGS

Ordered as SH70391, this is an AS568-391 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 21.953 in (557.61 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 22.373 in (568.27 mm). The 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) is known for an economical choice for high-volume maintenance programs and low compression set under sustained load. The material holds up against many alcohols, hydraulic fluids, and greases and lubricants. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). The profile itself contributes greater resistance to extrusion than a round section of the same size and simple lathe-cut manufacture at low tooling cost. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

It sees regular use in automotive, construction equipment, and hydraulic and pneumatic systems.

Stocked as SH70391 and sold individually. Nominal inside diameter is listed as 22 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.