What is perfluorinated rubber – FFKM/FFPM?

Perfluorinated rubbers, otherwise known as FFKM (according to ASTM 1418) or FFPM (according to ISO/DIN 1629) are perfluoroelastomer compounds containing an even higher amount of fluorine than FKM fluoroelastomers.

The Chrilaz® range

Specifically developed by ITC Elastomers, Chrilaz® perfluorinated elastomers combine the elastomeric properties of FFKM fluorocarbon and the chemical resistance of PTFE.

Two ranges are available:

  • Chrilaz® CHIM for improved chemical resistance
  • Chrilaz® THERM for high temperature resistance

Perfluorinated rubber – A very high performance elastomer

Perfluorinated rubber, FFKM or FFPM, has better resistance to high temperatures and chemicals than fluorocarbon rubbers, FKM or FPM. It even withstands environments where oxygen-plasma is present for many hours. Some grades have a maximum continuous service temperature of 320°C.

Summary of the properties of FFKM/FFPM perfluorinated rubbers


  • Use up to a peak of 320° C
  • Very good resistance to extrusion
  • Excellent resistance to water vapor
  • Good chemical resistance
  • Outstanding compression set at elevated temperatures
  • Operating temperature: 0°C to + 260°C


  • Poor cold resistance
  • Withstands dynamic applications
  • High price

Applications of FFKM/FFPM perfluorinated rubbers

The most efficient of fluoroelastomers, perfluorinated rubbers are used for vacuum applications, requiring very low contamination (degassing and particle emission) as well as operation at high temperatures (200–300 °C).

They are commonly used to make O-rings and rather static seals, used in applications involving contact with hydrocarbons or highly corrosive fluids, or for applications requiring resistance to a wide temperature range.

They have degassing performance similar to Teflon® (Teflon® is a registered trademark) while achieving vacuum tightness (permeability rate) similar to FKM compounds. This combination of properties allows FFKM seals to behave well under UHV pressures (UHV I don’t know) without using a metal seal.

The FFKM/FFPM perfluorinated rubber brands

Perfluorinated rubbers are also marketed under several brands, including the following:

  • Chrilaz®
  • Kalrez®,
  • Chemraz®,
  • Simriz®,
  • Technoflon
  • Dai-el