PTFE
ASTM D4894 · GB F4 · ISO 12086 · also Fluon, Hyflon
PTFE is a fully fluorinated semi-crystalline thermoplastic with essentially universal chemical inertness, the lowest coefficient of friction of any solid polymer (µ ≈ 0.05–0.10) and a very wide service window (–200 °C to +260 °C).
PTFE grades and fills
PTFE is supplied in 9 conditions, soft to hard.
- Bronze Filled
- MoS2 Filled
- Carbon Filled
- 30GF
- Polyimide Filled
- Glass Filled
- 30CF
- Graphite Filled
- Modified PTFE
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
40–60 % bronze powder PTFE | Pick for heavily loaded, high-PV dry bearings, wear rings and guide strips where thermal conduction and creep resistance matter more than chemical inertness. | 14 | 100 | 68 Shore D | |
MoS₂ Filled | Pick when hardness and wear must improve with almost no loss of virgin-PTFE strength, e.g. lightly loaded seals and static/dynamic gaskets. | 14 | 23 | 250 | 60 Shore D |
25 % carbon (carbon black/coke) PTFE | Pick for dry-running piston rings, compressor seals and hydraulic bearings needing high compressive strength, better heat removal and antistatic behaviour. | 15 | 120 | 64 Shore D | |
30% Glass Fiber | PTFE compound with 30 wt% milled glass fiber giving the lowest creep and wear of the standard glass grades while keeping electrical insulation and broad chemical resistance (except HF and hot alkali). | 15 | 220 | 64 Shore D | |
10–15 % PI PTFE | Pick for seals running against soft or polished shafts (aluminium, stainless, ceramic coatings) where abrasive fillers are unacceptable but creep must be reduced. | 15 | 25 | 250 | 60 Shore D |
15–25 % milled glass fibre PTFE | Pick for chemical-service seals, valve seats and slide bearings needing much lower creep and wear than virgin PTFE while keeping electrical insulation. | 17 | 250 | 62 Shore D | |
30% Carbon Fiber | PTFE compound with 30 wt% chopped carbon fiber for maximum creep/wear resistance, high thermal conductivity and antistatic behaviour in dry-running and hydraulic seal service. | 17 | 80 | 66 Shore D | |
10–15 % graphite PTFE | Pick for non-lubricated rotary and reciprocating seals against soft counterfaces — lowest friction of the filled grades with good water/steam service. | 17 | 200 | 58 Shore D | |
PPVE-modified, low-porosity | Pick for permeation-tight linings, high-purity semiconductor fluid handling and thin welded/fused parts — finer structure, less cold flow and better weldability than standard PTFE. | 33 | 430 | 57 Shore D |
Supply forms, finishes and certifications
Ways PTFE is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ePTFE | Expanded PTFE | Surface finish |
Food Grade | Food/Medical grade | Certification |
VirginDefault | Unfilled natural PTFE | Standard supply |
What is PTFE?
PTFE is a fully fluorinated semi-crystalline thermoplastic with essentially universal chemical inertness, the lowest coefficient of friction of any solid polymer (µ ≈ 0.05–0.10) and a very wide service window (–200 °C to +260 °C). It is chosen for seals, gaskets, chemical linings, bearings/slide plates and low-loss RF dielectrics. Its limits are low strength and stiffness, severe creep (cold flow) under sustained load, high thermal expansion, no melt processability (it is sintered, not injection moulded) and difficult bonding/welding — which is why filled compounds (glass, carbon, bronze, graphite) dominate mechanical applications. PTFE has a density of 2.17 g/cm³ (0.0784 lb/in³), heavier than 99% of polymer grades. Its glass-transition temperature is 126°C (259 °F). PTFE has a yield strength of 12 MPa (1.74 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 88% of polymer grades. Elongation at break is 350% and the elastic modulus is 0.5 GPa (0.0725 Msi).
What is PTFE used for?
- Seals
- Gaskets
- Liners
Advantages
- Good corrosion resistance — 98/100, better than 99% of polymer grades
- High service temperature — 260°C (500 °F), better than 97% of polymer grades
- Low moisture uptake — 0.01%, better than 97% of polymer grades
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- Ductile — tolerates forming and impact — 350%, better than 84% of polymer grades
Limitations
- Heavy — 2.17 g/cm³ (0.0784 lb/in³), worse than 99% of polymer grades
- High mold shrinkage — 4%, worse than 99% of polymer grades
- Hard to polish — 20/100, worse than 95% of polymer grades
- High embodied carbon — 9.5 kg CO₂/kg, worse than 89% of polymer grades
- Low strength — 12 MPa (1.74 ksi), worse than 88% of polymer grades
PTFE properties
Typical room-temperature values in the Virgin condition; bars are the position among polymer grades.
Physical6
PTFE has a density of 2.17 g/cm³ (0.0784 lb/in³), heavier than 99% of polymer grades. Its glass-transition temperature is 126°C (259 °F).
Mechanical15
PTFE has a yield strength of 12 MPa (1.74 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 88% of polymer grades. Elongation at break is 350% and the elastic modulus is 0.5 GPa (0.0725 Msi).
Thermal10
PTFE is rated for continuous service to 260°C (500 °F). It conducts heat at 0.25 W/m·K (0.144 BTU/hr·ft·°F), better than 72% of polymer grades. Thermal expansion is 130 µm/m·K (72.2 µin/in·°F).
Electrical7
PTFE is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹⁶ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (98/100), better than 99% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of PTFE takes about 210 MJ of energy and emits 9.5 kg of CO₂ — more than 89% of polymer grades. Typical recycled content is 0%.
Manufacturability6
PTFE's machinability is very good (80/100, better than 84% of polymer grades); weldability not recommended (10/100); formability very good (70/100).
Common Calculations5
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. PTFE is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PTFE
Is PTFE easy to machine?
Machines easily with sharp positive-rake tools and high speed/low feed, but is soft and springy — expect elastic recovery, burr rollover and thermal-expansion-driven dimensional drift; stress-relieve stock and allow 24 h relaxation before final gauging.
Can PTFE be welded?
Cannot be solvent-bonded or conventionally hot-plate welded; joining is by fusion sintering above 360 °C under pressure, mechanical clamping, or adhesive bonding only after chemical/plasma or sodium-naphthalene surface etch.
Can PTFE be formed, bent or molded?
Not injection mouldable (melt viscosity ~10¹¹ Pa·s): granular resin is compression-preformed and free-sintered at 360–380 °C, paste resin is ram/paste extruded, and billets are skived into film or turned/machined; sintering shrinkage 3–6 % must be allowed.
Manufacturability
The process limits FabDigit's quote engine applies to PTFE. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Good80 / 100 |
|---|---|
| ISO material group | N.8 |
| Cutting speed (rough / finish) | 400 / 500 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 10× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Not Recommend70 / 100 |
|---|---|
| Weldability | Not Recommend10 / 100 |
Injection molding
| Mold shrinkage | 1.5 – 2.2 % |
|---|---|
| Wall thickness | 1 – 3.5 mm |
| Recommended draft | 1.5 ° |
| Pre-drying | 80 °C for 4 h |
| UV resistance | Fair |
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 |
|---|---|---|
| Felemental fluorine content by weight | ≈ 76 | 76 |
| Celemental carbon content by weight | ≈ 24 | 24 |
| glass fiberonly in glass-filled compounds | 0 – 25 | 0 |
| carbon/graphiteonly in carbon/graphite-filled compounds | 0 – 25 | 0 |
| bronze (CuSn)only in bronze-filled bearing compounds | 0 – 60 | 0 |
| MoS2only in moly-filled compounds | 0 – 5 | 0 |
| tetrafluoroethylene (–CF2–CF2–) repeat uhomopolymer; modified PTFE contains ≤1 % PPVE/HFP comonomer | ≥ 99 (balance) |
What surface finishes work on PTFE?
Non-stick and non-paintable as moulded; use plasma, corona or sodium-etch pretreatment for printing/bonding, and expect no useful polish — surface finish is set by tooling and skiving quality.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Injection Molding Coating
Organic Coating
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PTFE in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- D4894
- ISO
- 12086
- GB (China)
- F4
- Trade names
- FluonHyflonTeflon
- Also called
- PolyflonPolytetrafluoroethylene
How much does PTFE cost?
PTFE is a premium-cost polymer ($$$), pricier than about 57% 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.
PTFE — frequently asked
What is PTFE used for?
PTFE is typically used for seals, gaskets and liners. In short: zero-friction; non-stick.
What is the yield strength of PTFE?
PTFE has a typical yield strength of 12 MPa (1.74 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 88% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is PTFE easy to machine?
Yes — machinability is rated very good (80/100, better than 84% of polymer grades). Machines easily with sharp positive-rake tools and high speed/low feed, but is soft and springy — expect elastic recovery, burr rollover and thermal-expansion-driven dimensional drift; stress-relieve stock and allow 24 h relaxation before final gauging.
Can PTFE be welded?
Not readily — weldability is rated not recommended (10/100). Cannot be solvent-bonded or conventionally hot-plate welded; joining is by fusion sintering above 360 °C under pressure, mechanical clamping, or adhesive bonding only after chemical/plasma or sodium-naphthalene surface etch.
What surface finishes work on PTFE?
Non-stick and non-paintable as moulded; use plasma, corona or sodium-etch pretreatment for printing/bonding, and expect no useful polish — surface finish is set by tooling and skiving quality.
Can PTFE be formed, bent or molded?
Not injection mouldable (melt viscosity ~10¹¹ Pa·s): granular resin is compression-preformed and free-sintered at 360–380 °C, paste resin is ram/paste extruded, and billets are skived into film or turned/machined; sintering shrinkage 3–6 % must be allowed.
What is the maximum service temperature of PTFE?
PTFE 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.
How much does PTFE cost?
PTFE is a premium-cost polymer ($$$), pricier than about 57% 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.
Can FabDigit make parts in PTFE?
Yes — PTFE is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM D4894 / D4895 — PTFE Molding and Extrusion Materials — ASTM International (2022)
- ASTM D1710 — PTFE Rod, Heavy-Walled Tubing and Basic Shapes — ASTM International (2019)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- Teflon PTFE fluoropolymer resin properties handbook — Chemours/DuPont (2021)
- TECAFLON PTFE stock shapes datasheet — Ensinger (2023)
- Dyneon PTFE / TFM modified PTFE product information — 3M Dyneon (2020)
- CAMPUS / plastics property datasets (fluoropolymers) — CWFG / CAMPUS consortium (2024)
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.