What is FKM?

FKM (Fluoroelastomer) is a high-performance synthetic rubber known for its excellent resistance to high temperatures, oils, fuels and a wide range of chemicals. The designation FKM is defined in ISO 1629. One of the best-known trade names is Viton®.

Thanks to its outstanding resistance to aggressive media, FKM is widely used in demanding sealing applications where standard elastomers such as NBR or EPDM are no longer suitable.

Properties of FKM

• Excellent temperature resistance (approximately -20 °C to +200 °C, depending on the compound even higher)
• Outstanding resistance to mineral oils, lubricants and fuels
• Very good resistance to many acids and chemicals
• Excellent resistance to ozone, weathering and ageing
• Low gas permeability
• Good compression set properties

Typical applications

FKM is commonly used for:

• O-rings
• Radial shaft seals
• Flat gaskets
• Moulded rubber parts
• Valve seals
• Hydraulic and pneumatic seals

Typical industries include:

• Automotive industry
• Chemical industry
• Mechanical engineering
• Aerospace
• Oil and gas industry
• Process industry

Limitations

FKM is generally not recommended for:

• Hot water
• Steam
• Glycol-based brake fluids
• Polar solvents such as acetone
• Certain amines and organic acids

For these applications, materials such as EPDM or FFKM are often more suitable.