*568-048 BUNA 70 SQUARE CUT RINGS

SH70048 is an AS568-048 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring built to an inside diameter of 4.739 in (120.37 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 4.879 in (123.93 mm). In service, this square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.

Expect good resistance to propane and butane, many alcohols, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in automotive brake fluid or ozone and direct sunlight. 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.

You will find this material specified across agricultural equipment, hydraulic and pneumatic systems, and general industrial maintenance.

Stocked as SH70048 and sold individually. Nominal inside diameter is listed as 4 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.