TFM-PTFE C25
Additive grade
also Dyneon TFM, Algoflon TFM
C25 = 25 % carbon (coke) filled, often + graphite
Pick for hydraulic seals, guide rings and unlubricated bearings where high load capacity and thermal conduction are required and no metallic filler is allowed.
Values for the C25 condition
Other TFM-PTFE grades and fills
TFM-PTFE is listed in 9 conditions; see the grade overview at TFM-PTFE.
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
fine-cut granular resin (compression moulding, ram extrusion) | Pick for thick compression-moulded billets, skived sheet/tape and ram-extruded rod/tube where highest mechanical properties and lowest porosity are needed. | 11 | 32 | 450 | 57 Shore D |
free-flow / agglomerated resin (automatic and isostatic moulding) | Pick for automatic filling of moulds, isostatic moulding of complex lined valves/pumps and large thin-wall parts. | 12 | 34 | 500 | 57 Shore D |
Carbon-black filled, static-dissipative / conductive | Pick where charge build-up must be bled off — solvent and fuel handling parts, semiconductor fluid components, explosive-atmosphere linings. | 12 | 20 | 200 | 60 Shore D |
Barium sulfate filled | Pick for high-purity chemical and food-contact seals needing lower cold flow than virgin resin plus X-ray detectability, without carbon or glass contamination. | 12 | 22 | 290 | 60 Shore D |
20 % carbon fibre filled modified PTFE | Pick for dry-running bearings, compressor piston rings and wear rings needing high creep resistance plus chemical compatibility with HF/alkali. | 13 | 17 | 120 | 65 Shore D |
15 % graphite filled modified PTFE | Pick for low-friction, non-stick-slip sliding seals and rotary lip seals in water/steam or lubricated service. | 13 | 18 | 200 | 60 Shore D |
C25This page 25 % carbon (coke) filled, often + graphite | Pick for hydraulic seals, guide rings and unlubricated bearings where high load capacity and thermal conduction are required and no metallic filler is allowed. | 13 | 15 | 110 | 64 Shore D |
40 % bronze filled modified PTFE | Pick for heavily loaded bearings/bushings and hydraulic guide rings in dry or oil service; not for aggressive acids or high-purity media (metal pick-up). | 14 | 16 | 150 | 66 Shore D |
25 % glass fibre filled modified PTFE | Pick for valve seats, piston rings and wear parts needing much lower creep/cold flow and better dimensional stability; avoid with hydrofluoric acid or strong alkali. | — | 17 | 250 | 62 Shore D |
What is TFM-PTFE C25?
TFM-PTFE C25 is TFM-PTFE in the C25 grade — pick for hydraulic seals, guide rings and unlubricated bearings where high load capacity and thermal conduction are required and no metallic filler is allowed. TFM-PTFE C25 has a tensile strength of 15 MPa (2.18 ksi), weaker than 74% of polymer grades. Elongation at break is 110% and the elastic modulus is 1.2 GPa (0.174 Msi). TFM-PTFE C25 has a density of 2.02 g/cm³ (0.073 lb/in³), heavier than 98% of polymer grades. Its glass-transition temperature is 126°C (259 °F).
Advantages
- Low moisture uptake — 0.01%, better than 100% of polymer grades
- Conducts heat well — 0.7 W/m·K (0.404 BTU/hr·ft·°F), better than 99% of polymer grades
- Good UV / weathering resistance — 96/100, better than 98% of polymer grades
- High service temperature — 260°C (500 °F), better than 97% of polymer grades
- Good corrosion resistance — 95/100, better than 97% of polymer grades
Limitations
- Heavy — 2.02 g/cm³ (0.073 lb/in³), worse than 98% of polymer grades
- High embodied carbon — 11 kg CO₂/kg, worse than 90% of polymer grades
- Difficult to weld — 5/100, worse than 89% of polymer grades
- Hard to polish — 30/100, worse than 82% of polymer grades
- High mold shrinkage — 2%, worse than 81% of polymer grades
TFM-PTFE C25 properties
Typical room-temperature values for TFM-PTFE C25; 26 are specific to this condition. Other listed values are TFM-PTFE reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
TFM-PTFE C25 has a density of 2.02 g/cm³ (0.073 lb/in³), heavier than 98% of polymer grades. Its glass-transition temperature is 126°C (259 °F).
Mechanical11
TFM-PTFE C25 has a tensile strength of 15 MPa (2.18 ksi), weaker than 74% of polymer grades. Elongation at break is 110% and the elastic modulus is 1.2 GPa (0.174 Msi).
Thermal10
TFM-PTFE C25 is rated for continuous service to 260°C (500 °F). It conducts heat at 0.7 W/m·K (0.404 BTU/hr·ft·°F), better than 99% of polymer grades. Thermal expansion is 80 µm/m·K (44.4 µin/in·°F).
Electrical7
TFM-PTFE C25 is an electrical insulator with a dielectric strength of 45 kV/mm (1,143 V/mil) and a resistivity of 100 Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (95/100), better than 97% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of TFM-PTFE C25 takes about 220 MJ of energy and emits 11 kg of CO₂ — more than 90% of polymer grades. Typical recycled content is 0%.
Manufacturability6
TFM-PTFE C25's machinability is good (58/100, worse than 55% of polymer grades); weldability not recommended (5/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TFM-PTFE C25
Is TFM-PTFE easy to machine?
Machines easily with very sharp, high positive-rake tools, high speed and light feeds; support thin walls, expect elastic recovery and hold tight temperature control since CTE is ~10× steel.
Can TFM-PTFE be welded?
Unlike conventional PTFE it can be fusion/thermal-bonded (hot plate, hot gas, or sinter bonding of overlaps) at 350–380 °C under pressure; no solvent bonding, adhesive joints need chemical or plasma etch.
Can TFM-PTFE be formed, bent or molded?
Not injection mouldable: free-sinter compression moulding, isostatic moulding or ram extrusion of billet, then sinter around 370 °C with slow cool; TFM's lower melt viscosity gives denser, void-free thick sections and better cold-flow resistance than PTFE.
What surface finishes work on TFM-PTFE?
No coating/plating adheres without surface activation — use sodium-naphthalene etch, corona or plasma treatment before bonding; parts are normally left as machined or skived, with mechanical clamping preferred over gluing.
TFM-PTFE 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 |
|---|---|---|
| perfluoro(propyl vinyl ether) PPVE comonmodifier that lowers melt viscosity and void content; PFA-type comonomer, may alternatively be PMVE/HFP in some brands | 0.02 – 1 | 0.1 |
| tetrafluoroethylene (TFE)polymer backbone | ≥ 99 (balance) | — |
TFM-PTFE C25 — frequently asked
What is TFM-PTFE C25 used for?
TFM-PTFE C25 is typically used for high-purity semiconductor components, precision-machined seals and liners, diaphragms and valve linings and skived film for lined vessels. In short: denser, less porous PTFE; weldable, unlike standard PTFE; better cold-flow resistance.
What is the tensile strength of TFM-PTFE C25?
TFM-PTFE C25 has a typical tensile strength of 15 MPa (2.18 ksi) — weaker than 74% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is TFM-PTFE C25 easy to machine?
Reasonably — machinability is rated good (58/100, worse than 55% of polymer grades). Machines easily with very sharp, high positive-rake tools, high speed and light feeds; support thin walls, expect elastic recovery and hold tight temperature control since CTE is ~10× steel.
Can TFM-PTFE C25 be welded?
Not readily — weldability is rated not recommended (5/100). Unlike conventional PTFE it can be fusion/thermal-bonded (hot plate, hot gas, or sinter bonding of overlaps) at 350–380 °C under pressure; no solvent bonding, adhesive joints need chemical or plasma etch.
What surface finishes work on TFM-PTFE C25?
No coating/plating adheres without surface activation — use sodium-naphthalene etch, corona or plasma treatment before bonding; parts are normally left as machined or skived, with mechanical clamping preferred over gluing.
Can TFM-PTFE C25 be formed, bent or molded?
Not injection mouldable: free-sinter compression moulding, isostatic moulding or ram extrusion of billet, then sinter around 370 °C with slow cool; TFM's lower melt viscosity gives denser, void-free thick sections and better cold-flow resistance than PTFE.
What is the maximum service temperature of TFM-PTFE C25?
TFM-PTFE C25 is rated for continuous use to about 260°C (500 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Dyneon PTFE TFM 1600 / 1700 modified PTFE product information — 3M Dyneon (2021)
- Algoflon TFM modified PTFE granular resins — Solvay Specialty Polymers (2022)
- ASTM D4894 – Standard Specification for PTFE Granular Molding and Ram Extrusion Materials — ASTM (2019)
- ASTM D4745 – Filled and Unfilled PTFE Molded Sheeting and Molded Basic Shapes — ASTM (2021)
- TECAFLON / fluoropolymer semi-finished product data — Ensinger (2023)
- Engineered Materials Handbook Vol. 2 – Engineering Plastics — ASM International (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.