568-439 BUNA 70 SQUARE CUT RINGS

Ordered as SH70439, this is an AS568-439 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 6.475 in (164.47 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 7.025 in (178.44 mm). The square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.

Buna-N (Nitrile) is widely chosen for an economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. The compound resists greases and lubricants, hydraulic fluids, and propane and butane. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where polar solvents or ketones are present. The profile itself contributes a flat contact band that spreads sealing load across a wider area and simple lathe-cut manufacture at low tooling cost. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

Common environments for this compound include agricultural equipment, automotive, and construction equipment.

Order part number SH70439, sold individually. Unit weight is approximately 23.8589 g. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.