568-321 BUNA 70 SQUARE CUT RINGS

This quad-ring is supplied in AS568-321 black Buna-N (Nitrile) 70 Shore A square profile with an inside diameter of 1.162 in (29.51 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.582 in (40.18 mm), catalogued under part number SH70321. It seats in a standard o-ring gland while offering improved dynamic performance.

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, hydraulic fluids, and greases and lubricants. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or polar solvents call for a different compound.

Maintenance and OEM teams specify it across general industrial maintenance, fluid power, and agricultural equipment.

Reference part number SH70321 when ordering; the item is sold individually. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.