The terms FPM, FKM and Viton® very often cause confusion and lead to incorrect interpretations. All of these designations actually stand for one single base material:fluorocarbon rubber.
FKM is the short form for the fluoroelastomer category according to the American standard ASTM and China standard..
FPM is the international abbreviation according to DIN/ISO.
Viton® is the registered trade mark of DuPont Performance Elastomers.
In china, we use name as FKM.