The SH70221 is an AS568-221 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring supplied with an inside diameter of 1.421 in (36.09 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.699 in (43.15 mm). This square-cut ring provides an economical lathe-cut alternative where a moulded o-ring is not required.
As a material, Buna-N (Nitrile) offers reliable performance in both static and dynamic service, an economical choice for high-volume maintenance programs. The material holds up against propane and butane, petroleum-based oils, and many alcohols. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving ozone and direct sunlight or strong acids call for a different compound. The profile itself contributes a flat contact band that spreads sealing load across a wider area 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 automotive, fluid power, and general industrial maintenance.
This item is sold individually under part number SH70221. Unit weight is approximately 1.7882 g and nominal inside diameter is listed as 1 7/16 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 568-221 BUNA 70 SQUARE CUT RINGS
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 1.421 inch (36.09 mm)
Actual_OD 1.699 inch (43.15 mm)
ProductCode Description O-Rings - Square/Quad - Commodity