Ordered as SH70369, this is an AS568-369 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 0.21 in (5.33 mm), and an outside diameter of 8.395 in (213.23 mm). The square-cut ring offers greater contact area against the gland wall than an equivalent o-ring.
The compound resists water, greases and lubricants, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) offers low compression set under sustained load and the most widely specified general-purpose sealing elastomer. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Exposure to strong acids or ketones will shorten service life. The profile itself contributes a rectangular section that will not roll in the groove and a flat contact band that spreads sealing load across a wider area. 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 hydraulic and pneumatic systems, automotive, and fluid power.
This item is sold individually under part number SH70369. Nominal inside diameter is listed as 8 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 568-369 BUNA 70 SQUARE CUT RINGS
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 7.975 inch (202.57 mm)
Actual_OD 8.395 inch (213.23 mm)
ProductCode Description O-Rings - Square/Quad - Commodity