Ordered as SH70445, this is an AS568-445 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 7.975 in (202.57 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 8.525 in (216.54 mm). The square-cut ring offers greater contact area against the gland wall than an equivalent o-ring.
Buna-N (Nitrile) delivers the most widely specified general-purpose sealing elastomer and low compression set under sustained load. It resists propane and butane, petroleum-based oils, and hydraulic fluids. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving strong acids 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.
Typical settings include automotive, general industrial maintenance, and fluid power.
Reference part number SH70445 when ordering; the item is sold individually. Unit weight is approximately 31.394 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Description 568-445 BUNA 70 SQUARE CUT RINGS
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 7.975 inch (202.57 mm)
Actual Outside Diameter 8.525 inch (216.54 mm)
Measurement System Imperial
Product Category O-Rings - Square/Quad - Commodity