Fluorocarbon Rubber (FKM) Viton®

ASTM D-2000 classification: HK


Temperature Range:

-26°C to +205°/230°C (-15°F to +400°/440°F)



Fluorocarbon elastomers have grown to major importance in the seal industry. Due to their extensive chemical compatibility, temperature capability, low compression set, and excellent ageing characteristics, fluorocarbon rubbers are the most significant single elastomers developed in recent history. Fluorocarbon elastomers are highly fluorinated carbon-based polymers used in applications to resist harsh chemical and ozone attack. Special compounds with improved chemical resistance are also available with new types always being developed. In general, with increasing fluorine content, resistance to chemical attack is improved but low temperature characteristics are diminished, however, speciality grade FKM’s are available that can provide high fluorine content with improved low temperature properties. The most well known brand of FKM is Viton®.



Fluorocarbon should be considered for use in aircraft, automobile and other mechanical applications requiring maximum resistance to elevated temperatures and too many fluids. FKM (FPM, Viton®, Fluorel®) resist mineral oils and greases, aliphatic, aromatic and special chlorinated hydrocarbons, petrol, diesel fuels, silicone oils and greases. It is also suitable for high vacuum applications.


Standard and Speciality Compounds

Type A and are commonly available in 75 & 90 Shore Hardness: – V75 & V90. These compounds are normally stocked in Black although other colours can be manufactured, i.e. Brown / Green. Other types are available

Type B - Generally used in Chemical Process plant, Power Utility Seals & Gaskets

Type F - Used for Oxygenated Automotive fuels. Concentrated aqueous inorganic acids, water, steam

Type ETP (also known as Viton® Extreme), offers excellent Chemical resistance and greater performance compared to standard compounds. Used for Automotive & Off Road – High pH lubricants, greases, & Coolants. Also used in Oil Exploration/ Production – Drilling Mud, Sour Wells. Special sealing requirements – solvents, coatings, ultra-harsh environments (ETP).

Additionally, speciality versions of these types are available to provide improved low temperature flexibility. These are called LT types, for example, GLT, and GFLT, and these perform like the A, and F families, respectively; GLT & GFLT have a wider temperature service range of – 35°C to 205°C.


EMI ReferenceSpecificationHardness IRHDSGTensile Strength (MPa)Elongation at Break %Colour
303 – F501Commercial50°1.1210450Red
303 – F502DTD 5612A50°1.1310430Brown
303 – V501Commercial50°1.1314450Red
303 – V502DTD 5612A50°1.1310430Brown
303 – V601Commercial60°1.1213330Black
303 – V602Commercial60°1.1213330Brown
303 – V603Viton A60°212290Black
303 – V651Commercial65°1.1210.3260Black
303 – V652O Ring Grade65°1.1211330Black
303 – V654Sheet Grade65°1.46200Black
303 – V656Viton FDA App65°214250White
303 – F701General FKM70°1.986200Black
303 – F702General FKM70°2.1715.8192Black
303 – V703Viton A70°1.955200Black
303 – V704Viton B70°1.818.5200Black
303 – F705FKM FDA70°1.838.46195White
303 - V706Viton FDA70°214250White
303 - V707General Purpose70°2.0113.5240To Order
303 - V708FDA Green70°2.2912200Green
303 - V709GFLTLow Temp70°1.8518228Black
303 – F751FKM Sheet75°1.8510175Black
303 – F752FKM O Ring75°1.937200Black
303 – V753Viton A75°1.8513170Black
303 – F754Extreme75°1.8918225Black
303 – V754Viton B75°1.913170Black
303 – F755FKM FDA75°1.8910175White
303 – F756FKM FDA75°1.8815270White

Full data sheets for all grades are available on request.

* The information above is supplied in good faith and believed to be correct. This information is supplied upon the condition that persons receiving this will make their own determination as to its suitability for their purposes prior to use. EMI makes no representations or warranties, either expressed or implied with respect to the information or the product to which this information refers.