568-249 FKM 75 SQUARE CUT RINGS

APG stocks the SV70249, an AS568-249 black Viton® (FKM) 70 Shore A Square-Cut Ring measuring an inside diameter of 4.859 in (123.42 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.137 in (130.48 mm). A square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

This material stands up to many acids, chlorinated solvents, and engine and transmission fluids. Viton® (FKM) is widely chosen for the industry benchmark where nitrile reaches its thermal limit, excellent resistance to compression set and permeation. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). Exposure to ketones and esters or amines will shorten service life. 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.

Typical settings include high-temperature process equipment, semiconductor equipment, and aerospace.

Stocked as SV70249 and sold individually. Nominal inside diameter is listed as 4 7/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.