Ordered as SH70283, this is an AS568-283 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 16.955 in (430.66 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 17.233 in (437.72 mm). The square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.
As a material, Buna-N (Nitrile) offers low compression set under sustained load and an economical choice for high-volume maintenance programs. The compound resists water, greases and lubricants, and petroleum-based oils. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It should not be specified for service in polar solvents or ketones. The profile itself contributes greater resistance to extrusion than a round section of the same size 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.
Typical settings include agricultural equipment, fluid power, and hydraulic and pneumatic systems.
Reference part number SH70283 when ordering; the item is sold individually. 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 568-283 BUNA 70 SQUARE CUT RINGS
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 16.955 inch (430.66 mm)
Actual Outside Diameter 17.233 inch (437.72 mm)
Measurement System Imperial
Product Category O-Rings - Square/Quad - Commodity