568-239 BUNA 70 SQUARE CUT RINGS

This square-cut ring is supplied in AS568-239 black Buna-N (Nitrile) 70 Shore A supplied with an inside diameter of 3.609 in (91.67 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.887 in (98.73 mm), catalogued under part number SH70239. It offers greater contact area against the gland wall than an equivalent o-ring.

Buna-N (Nitrile) is specified here for economical choice for high-volume maintenance programs and most widely specified general-purpose sealing elastomer. The material holds up against propane and butane, hydraulic fluids, and petroleum-based oils. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to ketones or automotive brake fluid will shorten service life. 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.

It sees regular use in hydraulic and pneumatic systems, general industrial maintenance, and construction equipment.

Reference part number SH70239 when ordering; the item is sold individually. Unit weight is approximately 4.3059 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.