Trade Names
  • Chemraz — Green, Tweed and Co.
  • Kalrez — DuPont
  • Tecnoflon PFR — Solvay
ASTM D1418 Designation
ASTM D2000/SAE J200 Type, Class
Apple Compound Designation
Standard Color
FFKM parts are made from a perfluoroelastomer possessing exceptional resistance to degradation by aggressive fluids and/or gases.
Key Uses
  • Seals for use in the chemical and petroleum industries as well as for the manufacturing of semiconductors and analytical and process instruments.
  • High temperature applications and for paint and coating operations.
Temperature Range
Standard Compound: -13°F to +600°F.
Hardness (Shore A)
65 to 90
  • FFKM combines the toughness of an elastomeric material with the chemical inertness of Teflon™.
  • It resists attack by nearly all chemical reagents and provides long-term service where corrosive additives can cause other elastomers to swell or degrade. In addition, FFKM parts are less likely to cold flow than Teflon™ seals.
  • Withstanding degradation by virtually ALL chemicals, FFKM can swell significantly when exposed to some fluorinated solvents, fully halogenated freons and uranium hexafluoride. In addition, FFKM parts should not be exposed to molten or gaseous alkali metals.
  • As the thermal coefficient of expansion for FFKM is stated by the manufacturer to be “about 50% greater than for fluoroelastomers”, gland volume may have to be increased to allow for this expansion in elevated temperature situations.
  • Because of its high cost, FFKM is generally used when no other elastomer is appropriate.