Perfluoroelastomer (FFKM, Kalrez™-type) combines the elasticity of rubber with chemical resistance approaching PTFE. FITCO supplies FFKM for critical, high-value process seals where failure is not an option — semiconductor processing, aggressive chemical service, and extreme-temperature applications across oil & gas and pharma.
| Temperature range | -15°C to +327°C |
|---|---|
| Hardness range | 70–90 Shore A |
| Relative cost | $$$$ |
| Resists | Virtually all process chemicals, solvents, steam, strong acids/bases, plasma |
| Avoid with | Elemental fluorine, molten alkali metals (extreme edge cases only) |
| Standards | AS568 / ISO 3601 / BS 4518 |
FFKM — Perfluoroelastomer isn't a single formulation — the grade below matters as much as the base compound once your application gets specific.
The entry point into perfluoroelastomer sealing — near-universal chemical resistance for process seals where FKM has already failed or the fluid list is too unpredictable to risk a lesser compound.
Formulated for minimal particulate and extractable generation, with plasma and aggressive etch-chemical resistance — specified for wafer processing chambers and other ultra-clean environments.
Optimized for sustained service at the highest end of FFKM's temperature capability, for reactor and high-temperature process valve seals where standard FFKM's margin is too thin.
Not sure which sub-grade fits your application? Send us your fluid, temperature and pressure and our engineers will confirm — send an enquiry →
Physical property data — hardness, tensile strength, elongation, compression set and temperature resistance — tested to ASTM/ISO standards for each hardness grade FITCO stocks.
Full physical property data sheet — hardness, tensile strength, elongation at break, compression set and temperature resistance.
Download Datasheet →Full physical property data sheet — hardness, tensile strength, elongation at break, compression set and temperature resistance.
Download Datasheet →General-purpose seal for mineral oils, fuels and hydraulic fluids.
-20°C to +200°CHigh-temperature, chemical-resistant sealing for oil & gas and process industries.
-40°C to +150°CWater, steam and weather-resistant sealing — the wrong choice for mineral oil.
Compare FFKM O-Rings against alternative compounds to confirm you have the right elastomer for your application.
FKM vs FFKM Comparison →Select standard, cross-section and ID — get instant OD and material readout for FFKM O-Rings.
Open Size Chart →Download the physical property datasheet for this compound — hardness, tensile strength, compression set and temperature resistance.
Download PDFs →Send us your fluid, temperature and pressure — our engineers will confirm the compound.
