FEPM
also Aflas
FEPM (Aflas) is a tetrafluoroethylene-propylene fluoroelastomer that resists amines, steam and strong bases far better than standard FKM, including amine- and H2S-bearing oilfield fluids.
Reference datasheet — FEPM is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SHA70 condition
FEPM grades and fills
FEPM is supplied in 7 conditions, soft to hard. SHA70 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Shore A 60 | Pick for low-pressure, low-clamp-force joints or rough sealing faces needing better conformability; the softer compound reaches 320 % elongation but resists extrusion less. | 13 | 320 | 15 Shore D | |
Low-temperature TFE/P/VDF terpolymer grade | Pick when sealing below −10 °C: the TFE/P/VDF terpolymer lowers Tg to −22 °C, but resistance to strong alkalis and amines drops and service is capped at 200 °C. | 15 | 260 | 22 Shore D | |
Wire & cable insulation / jacket compound | Pick for electric submersible pump cables and high-temperature nuclear or chemical-plant cable jackets needing high insulation, steam resistance and flame retardancy to 200 °C. | 15 | 250 | 30 Shore D | |
SHA70Default Shore A 70 | Use as the default general-purpose sealing hardness, balancing seal conformability against extrusion resistance, with 16 MPa tensile and service to 230 °C. | 16 | 250 | 22 Shore D | |
Shore A 80 | Choose for medium- and high-pressure oil and gas seals and grooves with clearance gaps, trading elongation down to 200 % for higher extrusion resistance at 18 MPa tensile. | 18 | 200 | 30 Shore D | |
Shore A 90 | Use for extreme-pressure or large-gap service and for back-up rings and seal support elements; 20 MPa tensile comes with elongation limited to 150 %. | 20 | 150 | 40 Shore D | |
AED/RGD | Choose for high-pressure gas wells and CO₂/H₂S service with rapid depressurisation, qualified to NORSOK M-710 / ISO 23936-2; elongation is limited to 160 %. | 20 | 160 | 40 Shore D |
Supply forms, finishes and certifications
Ways FEPM is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FDA | White / food-and-pharma contact compound | Certification |
What is FEPM?
FEPM (Aflas) is a tetrafluoroethylene-propylene fluoroelastomer that resists amines, steam and strong bases far better than standard FKM, including amine- and H2S-bearing oilfield fluids. Peroxide-cured compounds give about 16 MPa tensile strength and 250% elongation with service to 230 °C, and are supplied as O-rings, molded seals, packing elements and extruded cord in 60-90 Shore A grades, plus LT, AED, FDA and water-cure variants. Cost and availability are less favourable than FKM and cold service requires the LT grade. FKM remains the default where amines, steam and caustics are not present. FEPM has a density of 1.55 g/cm³ (0.056 lb/in³), heavier than 91% of polymer grades. Its glass-transition temperature is -3°C (27 °F). FEPM has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (0.0012 Msi).
What is FEPM used for?
- Oilfield downhole seals exposed to amines/H2S
- Steam and chemical process seals
- Automotive powertrain seals
- Semiconductor process seals
Advantages
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- High service temperature — 230°C (446 °F), better than 91% of polymer grades
- Good corrosion resistance — 92/100, better than 91% of polymer grades
- Ductile — tolerates forming and impact — 250%, better than 79% of polymer grades
Limitations
- Difficult to machine — 20/100, worse than 97% of polymer grades
- High mold shrinkage — 3%, worse than 97% of polymer grades
- High embodied carbon — 14 kg CO₂/kg, worse than 95% of polymer grades
- Heavy — 1.55 g/cm³ (0.056 lb/in³), worse than 91% of polymer grades
- Low stiffness — 0.01 GPa (0.0012 Msi), worse than 82% of polymer grades
FEPM properties
Typical room-temperature values for FEPM-SHA70; bars are the position among polymer grades.
Physical3
FEPM has a density of 1.55 g/cm³ (0.056 lb/in³), heavier than 91% of polymer grades. Its glass-transition temperature is -3°C (27 °F).
Mechanical8
FEPM has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (0.0012 Msi).
Thermal8
FEPM is rated for continuous service to 230°C (446 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 200 µm/m·K (111.1 µin/in·°F).
Electrical5
FEPM is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 91% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of FEPM takes about 290 MJ of energy and emits 14 kg of CO₂ — more than 95% of polymer grades. Typical recycled content is 0%.
Manufacturability4
FEPM's machinability is poor (20/100, worse than 97% of polymer grades); formability good (55/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. FEPM is highlighted; hover a dot for its name, or open the interactive family chart.
Working with FEPM
Is FEPM easy to machine?
After cure, work is limited to waterjet cutting, die cutting or low-temperature turning; the material is soft and highly resilient, so use sharp tooling, cryogenic support and generous tolerances.
Can FEPM be welded?
Not weldable; joints are spliced with uncured tape and heat-vulcanized, or bonded with fluoroelastomer-specific adhesive, and joint strength is below that of the parent rubber.
Can FEPM be formed, bent or molded?
Compression, transfer or injection mold with a peroxide press cure at 170-180 °C, followed by a mandatory post-cure of 4-16 h at 200-250 °C to lower compression set and drive off volatiles. Mooney viscosity is high, so mix thoroughly and vent the mold.
FEPM chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| tetrafluoroethylene (TFE)near-alternating with propylene; ~54–57 wt% F in polymer | 65 – 75 | 70 |
| vinylidene fluoride (VDF)present only in low-temperature terpolymer grades | 0 – 20 | 0 |
| carbon black (filler)phr in compound; mineral filler used in white/food grades | 0 – 30 | 20 |
| organic peroxide + TAIC coagentperoxide cure system (phr) | 1 – 5 | 3 |
| propylenecomonomer | ≥ 25 (balance) |
What surface finishes work on FEPM?
Cryogenic deflashing (freeze tumbling or blasting) is the normal route; PTFE or graphite coatings and plasma treatment can reduce friction. Do not clean with ketone or ester solvents, which swell the compound.
Equivalent designations
Standards and trade names that resolve to FEPM in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Aflas
How much does FEPM cost?
FEPM is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
FEPM — frequently asked
What is FEPM used for?
FEPM is typically used for oilfield downhole seals exposed to amines/H2S, steam and chemical process seals, automotive powertrain seals and semiconductor process seals. In short: base- and steam-resistant fluoroelastomer; 230 °C amine/H2S service; outlasts FKM in caustics.
What is the tensile strength of FEPM?
FEPM has a typical tensile strength of 16 MPa (2.32 ksi) — weaker than 72% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is FEPM easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of polymer grades). After cure, work is limited to waterjet cutting, die cutting or low-temperature turning; the material is soft and highly resilient, so use sharp tooling, cryogenic support and generous tolerances.
Can FEPM be welded?
Not weldable; joints are spliced with uncured tape and heat-vulcanized, or bonded with fluoroelastomer-specific adhesive, and joint strength is below that of the parent rubber.
What surface finishes work on FEPM?
Cryogenic deflashing (freeze tumbling or blasting) is the normal route; PTFE or graphite coatings and plasma treatment can reduce friction. Do not clean with ketone or ester solvents, which swell the compound.
Can FEPM be formed, bent or molded?
Compression, transfer or injection mold with a peroxide press cure at 170-180 °C, followed by a mandatory post-cure of 4-16 h at 200-250 °C to lower compression set and drive off volatiles. Mooney viscosity is high, so mix thoroughly and vent the mold.
What is the maximum service temperature of FEPM?
FEPM is rated for continuous use to about 230°C (446 °F), and briefly to 260°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does FEPM cost?
FEPM is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Aflas TFE/Propylene Fluoroelastomer — AGC Chemicals (2022)
- ASTM D1418 — Rubber and Rubber Latices Nomenclature (FEPM) — ASTM (2022)
- ASTM D2000 — Classification System for Rubber Products in Automotive Applications — ASTM (2020)
- NORSOK M-710 / ISO 23936-2 — Standards Norway / ISO (2020)
- Fluoroelastomers Handbook — The Definitive User's Guide — Elsevier/William Andrew (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.