568-218 FKM 75 SQUARE CUT RINGS

APG stocks the SV70218, an AS568-218 black Viton® (FKM) 70 Shore A Square-Cut Ring built to an inside diameter of 1.234 in (31.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.512 in (38.4 mm). A square-cut ring provides an economical lathe-cut alternative where a moulded o-ring is not required.

Expect good resistance to aromatic hydrocarbons, engine and transmission fluids, and aggressive chemicals. That behavior comes from the compound itself: Viton® (FKM) is valued for long service life in hot, chemically aggressive environments, excellent resistance to compression set and permeation. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to hot water and steam or amines will shorten service life. The profile itself contributes greater resistance to extrusion than a round section of the same size 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 automotive fuel systems, semiconductor equipment, and high-temperature process equipment.

Order part number SV70218, sold individually. Unit weight is approximately 1.8234 g. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.