PCTFE LMW-EXT
Grade
ASTM D1430 · also Kel-F, Neoflon
Use for thin-wall extrusion, wire insulation and injection-molded small parts where flow matters more than ultimate toughness.
Values for the LMW-EXT condition
Other PCTFE grades and fills
PCTFE is listed in 2 conditions; see the grade overview at PCTFE.
- HMW
- LMW-EXT
Compare all 2 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
High molecular weight compression-molding grade | Pick when maximum toughness, creep resistance and crack resistance are needed in thick machined stock shapes; hardest to process. | 33 | 39 | 140 | 77 Shore D |
LMW-EXTThis page lower molecular weight extrusion & injection grade | Use for thin-wall extrusion, wire insulation and injection-molded small parts where flow matters more than ultimate toughness. | 35 | 34 | 80 | 80 Shore D |
What is PCTFE LMW-EXT?
PCTFE LMW-EXT is PCTFE in the LMW-EXT grade — use for thin-wall extrusion, wire insulation and injection-molded small parts where flow matters more than ultimate toughness. PCTFE LMW-EXT has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 34 MPa (4.93 ksi) — weaker than 66% of polymer grades. Elongation at break is 80% and the elastic modulus is 1.6 GPa (0.232 Msi). PCTFE LMW-EXT has a density of 2.12 g/cm³ (0.0766 lb/in³), heavier than 98% of polymer grades. Its glass-transition temperature is 50°C (122 °F).
Advantages
- Low moisture uptake — 0.01%, better than 100% of polymer grades
- Good corrosion resistance — 95/100, better than 97% of polymer grades
- Good UV / weathering resistance — 92/100, better than 93% of polymer grades
- Easy to machine — 72/100, better than 76% of polymer grades
Limitations
- Heavy — 2.12 g/cm³ (0.0766 lb/in³), worse than 98% of polymer grades
- High embodied carbon — 13 kg CO₂/kg, worse than 93% of polymer grades
PCTFE LMW-EXT properties
Typical room-temperature values for PCTFE LMW-EXT; 24 are specific to this condition. Other listed values are PCTFE reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
PCTFE LMW-EXT has a density of 2.12 g/cm³ (0.0766 lb/in³), heavier than 98% of polymer grades. Its glass-transition temperature is 50°C (122 °F).
Mechanical13
PCTFE LMW-EXT has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 34 MPa (4.93 ksi) — weaker than 66% of polymer grades. Elongation at break is 80% and the elastic modulus is 1.6 GPa (0.232 Msi).
Thermal11
PCTFE LMW-EXT is rated for continuous service to 125°C (257 °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 65 µm/m·K (36.1 µin/in·°F).
Electrical7
PCTFE LMW-EXT is an electrical insulator with a dielectric strength of 21 kV/mm (533.4 V/mil) and a resistivity of 1×10¹⁶ 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 PCTFE LMW-EXT takes about 240 MJ of energy and emits 13 kg of CO₂ — more than 91% of polymer grades. Typical recycled content is 0%.
Manufacturability7
PCTFE LMW-EXT's machinability is very good (72/100, better than 76% of polymer grades); weldability poor (30/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PCTFE LMW-EXT
Is PCTFE easy to machine?
Machines cleanly with sharp positive-rake carbide tools, high speed and light feeds; more rigid and dimensionally stable than PTFE but notch-sensitive — avoid sharp internal corners and stress-relieve (anneal ~150 °C) before finish cuts.
Can PCTFE be welded?
No practical solvent or adhesive bonding without surface etching; joining is limited to hot-plate/fusion welding of thin sections, so parts are normally one-piece machined or mechanically sealed.
Can PCTFE be formed, bent or molded?
Very high melt viscosity and narrow window between melting (~212 °C) and thermal degradation (>300 °C); compression molding with slow controlled cooling is standard, injection/extrusion needs corrosion-resistant screws and tight temperature control.
What surface finishes work on PCTFE?
Not paintable or platable without plasma/chemical surface activation; typical finishing is precision machining and lapping of sealing faces plus annealing to relieve residual stress.
PCTFE 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.
| Element | Spec limit (wt %) |
|---|---|
| chlorotrifluoroethylene (CTFE) monomer u-(CF2-CFCl)n-; nominal 39% F, 30% Cl, 31% C by weight; no fillers or stabilizers in virgin grades | balance |
PCTFE LMW-EXT — frequently asked
What is PCTFE LMW-EXT used for?
PCTFE LMW-EXT is typically used for cryogenic valve seats, LOX and LH2 seals and gaskets, oxygen-system components, high-frequency insulators, pharmaceutical blister barrier film and chemical-resistant sight glasses and windows. In short: cryogenic chemical expert.
What is the yield strength of PCTFE LMW-EXT?
PCTFE LMW-EXT has a typical yield strength of 35 MPa (5.08 ksi) and a tensile strength of 34 MPa (4.93 ksi) — weaker than 66% of polymer grades. Strength varies by condition: see the 2 listed tempers.
Is PCTFE LMW-EXT easy to machine?
Yes — machinability is rated very good (72/100, better than 76% of polymer grades). Machines cleanly with sharp positive-rake carbide tools, high speed and light feeds; more rigid and dimensionally stable than PTFE but notch-sensitive — avoid sharp internal corners and stress-relieve (anneal ~150 °C) before finish cuts.
Can PCTFE LMW-EXT be welded?
Not readily — weldability is rated poor (30/100). No practical solvent or adhesive bonding without surface etching; joining is limited to hot-plate/fusion welding of thin sections, so parts are normally one-piece machined or mechanically sealed.
What surface finishes work on PCTFE LMW-EXT?
Not paintable or platable without plasma/chemical surface activation; typical finishing is precision machining and lapping of sealing faces plus annealing to relieve residual stress.
Can PCTFE LMW-EXT be formed, bent or molded?
Very high melt viscosity and narrow window between melting (~212 °C) and thermal degradation (>300 °C); compression molding with slow controlled cooling is standard, injection/extrusion needs corrosion-resistant screws and tight temperature control.
What is the maximum service temperature of PCTFE LMW-EXT?
PCTFE LMW-EXT is rated for continuous use to about 125°C (257 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in PCTFE LMW-EXT?
Yes — PCTFE LMW-EXT is available for CNC machining, sheet metal and injection molding; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Neoflon CTFE (PCTFE) resin data — M-300P / M-400H — Daikin Industries (2021)
- Kel-F 81 / PCTFE stock shape properties — Arkema / 3M legacy data (2015)
- Engineered Materials Handbook Vol.2: Engineering Plastics — ASM International (1988)
- Aclar PCTFE barrier film technical data — Honeywell (2020)
- ASTM D1430 — Standard Classification System for Polychlorotrifluoroethylene (PCTFE) Plastics — ASTM (2019)
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.