568-220 BUNA 70 SQUARE CUT RINGS

Ordered as SH70220, this is an AS568-220 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 1.359 in (34.52 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.637 in (41.58 mm). The square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.

Buna-N (Nitrile) is specified here for low compression set under sustained load, reliable performance in both static and dynamic service. The compound resists hydraulic fluids, water, and greases and lubricants. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). 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.

It sees regular use in general industrial maintenance, agricultural equipment, and hydraulic and pneumatic systems.

Reference part number SH70220 when ordering; the item is sold individually. Unit weight is approximately 1.6767 g. 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.