Viton™ is a high quality and high performance rubber compound. Fluoroelastomer (FKM) (FPM)
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 fluoro rubber.
FPM is the international abbreviation according to DIN/ISO, whereas
FKM is the short form for the fluoroelastomer category according to the American standard ASTM.
Viton™ is the registered trade mark of Chemours from November 2016, previously Dupont Performance Elastomers.

In general terms for gasket making we use genuine Viton™ A or Viton™ B and a high quality FKM sheet. (Fluor-A Com®)
Viton™ A: (vinylidene fluoride and hexafluoropropylene) Viton A is a family of fluoroelastomer di-polymers that is polymerised from two monomers, Vinylidene fluoride (VF2) and Hexafluoropropylene (HFP). VitonA is a 100% compound with a 66% fluorine content that is suited for general moulded goods such as O-rings and v-rings and gaskets
Viton™ B: (vinylidene, hexafluoropropylene and tetrafluoroethylene) Viton B is a grade of fluoroelastomer terpolymers that is polymerised from three monomers, Vinylidene (VF2), Hexafluoropropylene (HFP), and Tetrafluoroethylene (TFE). Viton B fluoroelastomers offer better fluid resistance than A type fluoroelastomer.
Both grades are black in colour and have a +250 C high temperature limit. VitonA has a lower limit of -30C whilst VitonB is less at -15C.

We also cut WHITE FOOD QUALITY Viton® 65°/70 Durometer, 66% fluorine, 100% Virgin Fluoroelastomer compound intended for repeated food contact in food grade applications and is formulated to meet FDA guidelines as described in the Code of Federal Regulations 21 CFR 177.2600. After vulcanising the material is post cured for 8 hours at 180°C. The temperature range is -10 to +250C

SPONGE Viton™ is also available in medium density form. This sponge is a closed cell sponge with a continuous skin on both sides. The Temperature range is -25 to 200C