Surface finish requirements on sealing surfaces directly impact FFKM O-ring performance and longevity. Dynamic applications require 8 to 16 microinch Ra finishes. Static seals tolerate 32 to 63 microinch Ra surfaces. Excessive roughness accelerates wear and creates leak paths. Overly smooth finishes may not retain lubricating films. Hard chrome or electroless nickel plating on dynamic... https://globalsealstech.com/ffkm-seals/