568-149 BUNA 70 SQUARE CUT RINGS

APG stocks the SH70149, an AS568-149 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 2.8 in (71.12 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 3.006 in (76.35 mm). A square-cut ring presents a flat rectangular section that cannot roll or twist in its groove, making it a dependable static seal.

Buna-N (Nitrile) is specified here for low compression set under sustained load and most widely specified general-purpose sealing elastomer. The material holds up against petroleum-based oils, propane and butane, and many alcohols. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving polar solvents or ketones call for a different compound. 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 automotive, construction equipment, and agricultural equipment.

SH70149 ships individually. Unit weight is approximately 1.8169 g and nominal inside diameter is listed as 2 13/16 inch. Review your operating media and conditions against this specification before installation.