568-157 BUNA 70 SQUARE CUT RINGS

This square-cut ring is supplied in AS568-157 black Buna-N (Nitrile) 70 Shore A with an inside diameter of 4.487 in (113.97 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 4.693 in (119.2 mm), catalogued under part number SH70157. It resists the spiral failure that affects round rings on long reciprocating strokes.

Buna-N (Nitrile) is specified here for reliable performance in both static and dynamic service, most widely specified general-purpose sealing elastomer. Expect good resistance to water, greases and lubricants, and propane and butane. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or ketones call for a different compound. The profile itself contributes a rectangular section that will not roll in the groove 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 fluid power, general industrial maintenance, and agricultural equipment.

Stocked as SH70157 and sold individually. Unit weight is approximately 2.43 g. Application requirements vary, so validate compatibility with your process conditions prior to installation.