568-321 BUNA 70 SQUARE CUT RINGS

This square-cut ring is supplied in AS568-321 black Buna-N (Nitrile) 70 Shore A 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 provides an economical lathe-cut alternative where a moulded o-ring is not required.

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. The profile itself contributes simple lathe-cut manufacture at low tooling cost 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.

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.