FKM 4 - Fluoroelastomer terpolymer of tetrafluoroethylene, propylene & vinylidene fluoride
Clwyd reference | FKM 4 |
ASTM classification | FKM 4 |
Terpolymer of tetrafluoroethylene (TFE), propylene (P) and vinylidene fluoride (VF2/VDF). While base resistance is increased in type 4 FKMs, their swelling properties especially in hydrocarbons are worsened. Typically they have a fluorine content of about 67 weight percent. | |
Typical applications | |
Advantages | |
Disadvantages | |
Available hardness range (Shore A) | 60 - 95 |
Upper continuous service temp. | 250°C |
Min. temp. for sealing applications | -5°C |
Minimum non-brittle temp. | -10°C |
Tensile strength (up to) | 20 MPa |
Elongation at break (up to) | 250% |
Price Bracket | Medium |
ASTM 1 Oil | Excellent |
ASTM 2 Oil | Excellent |
ASTM 3 Oil | Excellent |
Kerosene | Excellent |
Liquid B | Excellent |
Liquid 101 | Excellent |
Phosphate ester | None |
Ketone | None |
Toluene | Excellent |
Iso-octane | Excellent |
Methanol | Excellent |
Acid (weak) | Excellent |
Acid (strong) | Excellent |
Base (weak) | None |
Base (strong) | None |
Hydrogen sulphide | None |
Steam | None |
Ozone | Excellent |
Radiation | Excellent |