568-121 BUNA 70 SQUARE CUT RINGS

APG stocks the SH70121, an AS568-121 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 1.049 in (26.64 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.255 in (31.88 mm). A square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.

As a material, Buna-N (Nitrile) is valued for an economical choice for high-volume maintenance programs, strong abrasion and tear resistance. It resists propane and butane, petroleum-based oils, and many alcohols. Continuous operating temperature is published at -40°F (-40°C) to 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.

You will find this material specified across general industrial maintenance, construction equipment, and agricultural equipment.

Order part number SH70121, sold individually. Unit weight is approximately 0.7082 g and nominal inside diameter is listed as 1 1/16 inch. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.