APG stocks the SH70210, an AS568-210 black Buna-N (Nitrile) 70 Shore A Square-Cut Ring built to an inside diameter of 0.734 in (18.64 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.012 in (25.7 mm). A square-cut ring offers greater contact area against the gland wall than an equivalent o-ring.
Expect good resistance to hydraulic fluids, many alcohols, and propane and butane. Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Applications involving ozone and direct sunlight or polar solvents call for a different compound. 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 general industrial maintenance, construction equipment, and automotive.
Reference part number SH70210 when ordering; the item is sold individually. Unit weight is approximately 0.9976 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Description 568-210 BUNA 70 SQUARE CUT RINGS
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 0.734 inch (18.64 mm)
Actual Outside Diameter 1.012 inch (25.7 mm)
Measurement System Imperial
Product Category O-Rings - Square/Quad - Commodity