568-218 BUNA 70 SQUARE CUT RINGS

Ordered as SH70218, this is an AS568-218 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 1.234 in (31.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.512 in (38.4 mm). The square-cut ring presents a flat rectangular section that cannot roll or twist in its groove, making it a dependable static seal.

As a material, Buna-N (Nitrile) offers the most widely specified general-purpose sealing elastomer and low compression set under sustained load. Expect good resistance to many alcohols, hydraulic fluids, and propane and butane. 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 a rectangular section that will not roll in the groove. 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 hydraulic and pneumatic systems, fluid power, and general industrial maintenance.

This item is sold individually under part number SH70218. Unit weight is approximately 1.2358 g and nominal inside diameter is listed as 1 1/4 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.