PCTFE · grade · default condition
PCTFE Unfilled
Properties of the Unfilled condition, compared with the other PCTFE grades.
Standard choice for cryogenic seals, valve seats, oxygen-service and high-frequency insulating parts machined from compression-molded stock.
What is PCTFE Unfilled?
PCTFE Unfilled is PCTFE in the Unfilled grade — standard choice for cryogenic seals, valve seats, oxygen-service and high-frequency insulating parts machined from compression-molded stock. PCTFE Unfilled has a yield strength of 34 MPa (4.93 ksi) and a tensile strength of 37 MPa (5.37 ksi) — weaker than 70% of polymer grades. Elongation at break is 110% and the elastic modulus is 1.5 GPa (0.218 Msi). PCTFE Unfilled 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
- High service temperature — 135°C (275 °F), better than 75% 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
- Difficult to weld — 20/100, worse than 78% of polymer grades
PCTFE Unfilled properties
Typical room-temperature values for PCTFE Unfilled — 6 properties are specific to this condition; the rest are grade-level values shared by every PCTFE grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical6
PCTFE Unfilled 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 Unfilled has a yield strength of 34 MPa (4.93 ksi) and a tensile strength of 37 MPa (5.37 ksi) — weaker than 70% of polymer grades. Elongation at break is 110% and the elastic modulus is 1.5 GPa (0.218 Msi).
Thermal11
PCTFE Unfilled is rated for continuous service to 135°C (275 °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 Unfilled 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 Unfilled takes about 240 MJ of energy and emits 13 kg of CO₂ — more than 92% of polymer grades. Typical recycled content is 0%.
Manufacturability7
PCTFE Unfilled's machinability is very good (70/100, better than 73% of polymer grades); weldability poor (20/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other PCTFE grades and fills
PCTFE is also supplied in 4 other conditions. The full side-by-side table is on the PCTFE overview.
- UnfilledDefaultStandard choice for cryogenic seals, valve seats, oxygen-service and high-frequency insulating parts machined from compression-molded stock.37 MPa tensile
Working with PCTFE Unfilled
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 Unfilled — frequently asked
What is PCTFE Unfilled used for?
PCTFE Unfilled 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 Unfilled?
PCTFE Unfilled has a typical yield strength of 34 MPa (4.93 ksi) and a tensile strength of 37 MPa (5.37 ksi) — weaker than 70% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is PCTFE Unfilled easy to machine?
Yes — machinability is rated very good (70/100, better than 73% 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 Unfilled be welded?
Not readily — weldability is rated poor (20/100). 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 Unfilled?
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 Unfilled 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 Unfilled?
PCTFE Unfilled is rated for continuous use to about 135°C (275 °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 Unfilled?
Yes — PCTFE Unfilled 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
- 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.