Ordered as SH70143, this is an AS568-143 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring measuring an inside diameter of 2.425 in (61.6 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.631 in (66.83 mm). The square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.
The material holds up against petroleum-based oils, water, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for low compression set under sustained load, reliable performance in both static and dynamic service. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where automotive brake fluid or ketones are present. The profile itself contributes simple lathe-cut manufacture at low tooling cost and greater resistance to extrusion than a round section of the same size. 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 agricultural equipment, general industrial maintenance, and automotive.
Stocked as SH70143 and sold individually. Unit weight is approximately 1.36 g. Check the compound against your process media, pressure and temperature before committing to a design.
description 568-143 BUNA 70 SQUARE CUT RINGS
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 2.425 inch (61.6 mm)
Actual_OD 2.631 inch (66.83 mm)
ProductCode Description O-Rings - Square/Quad - Commodity