568-256 BUNA 70 SQUARE CUT RINGS

Part number SH70256 is an AS568-256 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 5.734 in (145.64 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.012 in (152.7 mm). A square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.

Buna-N (Nitrile) is known for low compression set under sustained load, reliable performance in both static and dynamic service. It resists many alcohols, greases and lubricants, and petroleum-based oils. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). 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 fluid power, agricultural equipment, and general industrial maintenance.

Order part number SH70256, sold individually. Unit weight is approximately 5.671 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.