Ordered as SH70349, this is an AS568-349 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring built to an inside diameter of 4.475 in (113.67 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.895 in (124.33 mm). The square-cut ring provides an economical lathe-cut alternative where a moulded o-ring is not required.
Buna-N (Nitrile) is specified here for reliable performance in both static and dynamic service, economical choice for high-volume maintenance programs. The material holds up against water, greases and lubricants, and propane and butane. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). The profile itself contributes simple lathe-cut manufacture at low tooling cost 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.
It sees regular use in hydraulic and pneumatic systems, general industrial maintenance, and construction equipment.
Stocked as SH70349 and sold individually. Unit weight is approximately 12.326 g and nominal inside diameter is listed as 4 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 568-349 BUNA 70 SQUARE CUT RINGS
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 4.475 inch (113.67 mm)
Actual_OD 4.895 inch (124.33 mm)
ProductCode Description O-Rings - Square/Quad - Commodity