FEP vs PCTFE
Polymer · grade comparison
FEP and PCTFE are both polymer grades. PCTFE is the stronger of the two: yield strength 34 MPa (4.93 ksi) against 13 MPa (1.89 ksi) for FEP, about 162% more; tensile strength follows at 37 MPa (5.37 ksi) vs 23 MPa (3.34 ksi). In exchange, FEP is the more ductile: elongation 320% versus 110% for PCTFE, and PCTFE is harder (78 Shore D vs 56 Shore D). PCTFE is stiffer (1.5 GPa vs 0.48 GPa) and FEP runs hotter in service (200°C vs 135°C continuous). On the shop floor, PCTFE machines more easily (very good vs good) and FEP welds better (very good vs poor).
FEPChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
PCTFEChoose it when strength drives the design, or when the part is machined in volume.
FEP vs PCTFE: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Compressive Modulus
Flexural Strength
Shear Strength
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Refractive Index
Light Transmission
Same in both: Water Absorption (Saturation) 0.01%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Max Service Temperature (short-term)
Vicat Softening Point (B50)
Same in both: Limiting Oxygen Index 95%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁶ Ω·m3.94×10²³ µΩ·in · Volume Resistivity 1×10¹⁸ Ω·cm · Surface Resistivity 1×10¹⁶ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | FEP | PCTFE |
|---|---|---|
| Default condition | Unfilled | Unfilled |
| Relative cost | $$$$$ Specialty | $$$$$ Specialty |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining, Sheet metal and Injection molding. Both take the same 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
FEP vs PCTFE — frequently asked
Is PCTFE stronger than FEP?
Yes. PCTFE has a typical yield strength of 34 MPa (4.93 ksi) against 13 MPa (1.89 ksi) for FEP — about 162% more. Tensile strength is 37 MPa (5.37 ksi) vs 23 MPa (3.34 ksi).
Which is cheaper, FEP or PCTFE?
Both sit in the same relative cost tier ($$$$$, specialty); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, FEP or PCTFE?
PCTFE. Its machinability rates very good (70/100) against good (55/100) for FEP; for welding the order is FEP first (very good, 80/100) then PCTFE (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in FEP and PCTFE side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.