This o-ring is supplied in AS568-243 black Viton® (FKM) 75 Shore A measuring an inside diameter of 4.109 in (104.37 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.387 in (111.43 mm), catalogued under part number V75243. It seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.
This material stands up to petroleum oils and fuels, many acids, and chlorinated solvents. That behavior comes from the compound itself: Viton® (FKM) offers outstanding high-temperature capability and the industry benchmark where nitrile reaches its thermal limit. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. It should not be specified for service in ketones and esters or amines.
Maintenance and OEM teams specify it across chemical processing, semiconductor equipment, and high-temperature process equipment.
Order part number V75243, sold individually. Nominal inside diameter is listed as 4 1/8 inch. 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 -243 BLACK FKM 75D O-RING
uf_description2 0.139" (3.53MM) CS X 4.109" (104.37MM) ID
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 4.109 inch (104.37 mm)
Actual_OD 4.387 inch (111.43 mm)
ProductCode Description O-Rings - Bulk - Commodity