FKM (Viton-type) rubber
FKM (Viton-type) fluoroelastomer is the compound for the hardest duty: high heat together with oil, fuel or chemical exposure. Exonel moulds and extrudes FKM (Viton-type) compounds into seals, gaskets and O-rings for fuel systems, process equipment and high-temperature industrial parts.
Indicative ranges. The exact grade and hardness are matched to your application.
Six base polymers, compared.
Temperature range, hardness and resistance for typical commercial compounds of each polymer. Ratings run from A (excellent) to X (not suitable).
| Material | Temp range (°C) | Hardness (Shore A) | Oil | Fuel | Acid | Base | Water / steam | Ozone / weather |
|---|---|---|---|---|---|---|---|---|
| Silicone (VMQ) | −60 to +225 | 20 to 90 | C | D | C | C | B | A |
| EPDM | −45 to +150 | 30 to 90 | X | X | A | A | A | A |
| FKM (Viton-type) | −20 to +200 | 50 to 95 | A | A | A | C | C | A |
| NBR | −40 to +120 | 20 to 100 | A | B | C | B | B | D |
| Neoprene (CR) | −40 to +120 | 15 to 95 | B | C | C | B | B | B |
| SBR | −50 to +100 | 30 to 100 | X | X | C | B | B | D |
Key: A Excellent · B Good · C Fair · D Poor · X Not suitable
Figures are the typical range across commercial compounds. Special grades extend several of these limits: silicone to −117°C and +260°C, FKM to −40°C, NBR to −57°C. Figures are indicative and are confirmed for your application before tooling.
Sources: o-ring.info, Basic properties of elastomers; Mykin Inc, Rubber properties; Delta Rubber, Rubber material comparison guide; GMORS, VMQ silicone (silicone temperature range).
For the harshest service.
Chemical resistance
Stands up to fuels, oils, solvents and many aggressive chemicals.
High heat
Holds sealing performance at sustained high temperature.
Petroleum duty
A default for fuel-system and processing seals.
Low compression set
Keeps sealing under heat and pressure.
Moulded and extruded.
Moulded
O-rings, seals and gaskets to drawing.
Extruded
Profiles and cords for chemical and high-heat sealing.
Where it fits.
Automotive and fuel
Fuel-system and high-heat engine seals.
Chemical and process
Seals exposed to solvents and aggressive media.
Industrial OEMs
High-temperature sealing to specification.
Where we would point you elsewhere.
Low temperature and steam
FKM stiffens in deep cold and is not ideal for steam. Use silicone or EPDM.
Common questions
What is FKM used for?
Is Viton the same as FKM?
Does FKM work in the cold?
Need an FKM part?
Send your RFQ
Tell us what you need. Fields marked * are required. Everything else helps us recommend the compound.
Exonel Industries makes custom moulded and extruded rubber components in Howrah, Kolkata, West Bengal, and supplies manufacturers across India. We work in six base polymers, Silicone, EPDM, FKM, NBR, Neoprene and SBR, formulated into hundreds of compounds. Compounding, tooling and production are done in-house. Send a drawing, a sample or a specification for a quote.
