This square-cut ring is supplied in AS568-338 black Viton® (FKM) 70 Shore A built to an inside diameter of 3.1 in (78.74 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 3.52 in (89.41 mm), catalogued under part number SV70338. It presents a flat rectangular section that cannot roll or twist in its groove, making it a dependable static seal.
This material stands up to chlorinated solvents, aromatic hydrocarbons, and petroleum oils and fuels. That behavior comes from the compound itself: Viton® (FKM) delivers excellent resistance to compression set and permeation, very low compression set at elevated temperature. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where ketones and esters or low-molecular-weight organic acids are present. The profile itself contributes a rectangular section that will not roll in the groove and simple lathe-cut manufacture at low tooling cost. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.
You will find this material specified across semiconductor equipment, chemical processing, and high-temperature process equipment.
Reference part number SV70338 when ordering; the item is sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation.
description 568-338 FKM 75 SQUARE CUT RINGS
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 3.1 inch (78.74 mm)
Actual_OD 3.52 inch (89.41 mm)
ProductCode Description O-Rings - Square/Quad - Commodity