Perfluoroelastomer — PTFE-Level Chemical Inertness in Elastomer Form
FFKM (Perfluoroelastomer)
FFKM perfluoroelastomers combine the chemical inertness of PTFE with the sealing resilience of an elastomer. We supply FFKM gaskets and seals for semiconductor, pharmaceutical, and aggressive chemical processing applications where standard FKM is insufficient.
At a Glance
Temperature Range
-25 °C to +325 °C continuous
Hardness Range
70–95 Shore A
Available Forms
Brands We Stock
Technical Properties
Typical values across stocked grades. Specific grade data sheets available on request.
Physical Characteristics
Density
1.85–2.05 g/cm³ (ASTM D792)
Tensile Strength
10–20 MPa (ASTM D412)
Elongation at Break
100–200% (ASTM D412)
Compression Set
15–35% at 200 °C / 70 h (ASTM D395)
Chemical Resistance
Resistant To
- Virtually all organic solvents (ketones, esters, ethers, amines)
- Concentrated acids (sulphuric, hydrochloric, nitric, hydrofluoric)
- Concentrated alkalis (sodium hydroxide, potassium hydroxide)
- Oxidising agents (hydrogen peroxide, chlorine, bromine)
- Saturated steam to ~250 °C continuous on most grades; up to ~300 °C on premium grades like Kalrez 6375 (verify pressure and duration for specific compound)
- Petroleum oils, fuels, and hydraulic fluids
- Aromatic hydrocarbons (benzene, toluene, xylene)
- Halogenated solvents (chloroform, methylene chloride)
Limited Resistance
- Some perfluorinated solvents at extreme temperature
- Amine-based solvents at elevated temperature (grade-dependent; verify with compound supplier)
Not Recommended
- Molten alkali metals (sodium, potassium, lithium)
- Elemental fluorine gas at high pressure and temperature
- Interhalogen fluorinating agents (chlorine trifluoride ClF₃, bromine trifluoride BrF₃)
- Fully fluorinated solvents (FC-75, perfluoro ethers) — swelling and extraction
- Oxidising propellants such as nitrogen tetroxide (N₂O₄)
- Uranium hexafluoride (UF₆) and nitrogen trifluoride (NF₃) at elevated temperature
Environmental Ratings
Weather Resistance
Handles UV, ozone, and weather without degradation
Ozone Resistance
Fully inert to ozone. The fluorinated backbone doesn't react.
UV Resistance
No degradation from UV exposure
Standards & Certifications
Standards Compliance
Certifications
Common Applications
- Semiconductor wafer processing equipment seals
- Pharmaceutical reactor and CIP/SIP seals
- Aggressive chemical processing where FKM is attacked
- Hot acid and mixed-solvent service gaskets
- Plasma etch chamber seals
- High-purity and ultra-clean process seals
- Amine and ketone service where FKM swells
- Nuclear process sealing (verify radiation dose tolerance for specific grade)
Not Recommended For
- Extremely high material cost: typically 20–50× the price of FKM for standard grades. Only justified where FKM fails chemically.
- Limited elongation (100–200%) compared to general-purpose elastomers, which rules it out for large-stretch dynamic seals
- Longer lead times on non-standard sizes. Predominantly supplied as moulded O-rings and custom gaskets.
- Lower tear strength than standard rubbers; handle with care during installation
- Not stocked as sheet rubber — supplied as moulded parts and die-cut gaskets to order
Available Grades
Brands we stock: Kalrez (Chemours), Chemraz (Greene Tweed), Perlast (PPE), Isolast (Trelleborg), Simriz (Freudenberg), Parofluor (Parker), Markez (Marco Rubber)
FFKM Standard (75 Shore A)
The workhorse FFKM grade — 75 Shore A, typical Kalrez 6375 / Chemraz 505 class, rated to +275 °C continuous, handles the widest chemical range. Start here when FKM can't cope with the process media. Premium grades like Kalrez 4079 (+316 °C) and 7075 (+327 °C) extend the upper limit.
FFKM High-Temperature
Holds its seal above 300 °C where the standard grade's compression set starts to climb. Typically specified in aggressive CPI reactors and high-temperature pharmaceutical processes.
FFKM FDA / USP Grade
Food SafeFood and pharmaceutical-grade FFKM meeting FDA 21 CFR 177.2600 and USP Class VI requirements. White or translucent compound for clean-process applications.
Need FFKM (Perfluoroelastomer)?
We supply ffkm (perfluoroelastomer) in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.
Disclaimer
This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.