Wholesale FKM O Ring — Fluororubber Sealing for Demanding Environments High-performance FKM (fluororubber) O rings engineered for continuous service under elevated temperatures and aggressive media. Ideal for piping, fuel systems, and heavy industry sealing where reliability and long service life are critical. Key Features of FKM Fluororubber O Rings High-temperature tolerance: Performs continuously under sustained high-heat operating conditions. Chemical resistance: