APG stocks the SV70284, an AS568-284 black Viton® (FKM) 70 Shore A Square-Cut Ring built to an inside diameter of 17.955 in (456.06 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 18.233 in (463.12 mm). A square-cut ring presents a flat rectangular section that cannot roll or twist in its groove, making it a dependable static seal.
The material holds up against many acids, aromatic hydrocarbons, and aggressive chemicals. That behavior comes from the compound itself: Viton® (FKM) delivers the industry benchmark where nitrile reaches its thermal limit and long service life in hot, chemically aggressive environments. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in ketones and esters or low-molecular-weight organic acids. 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.
Common environments for this compound include automotive fuel systems, aerospace, and semiconductor equipment.
SV70284 ships individually. 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 568-284 FKM 75 SQUARE CUT RINGS
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 17.955 inch (456.06 mm)
Actual_OD 18.233 inch (463.12 mm)
ProductCode Description O-Rings - Square/Quad - Commodity