FEP vs PFA
Polymer · grade comparison
FEP and PFA are both polymer grades, both corrosion resistant plastic. PFA is the stronger of the two: yield strength 14 MPa (2.03 ksi) against 13 MPa (1.89 ksi) for FEP, about 8% more; tensile strength follows at 30 MPa (4.35 ksi) vs 23 MPa (3.34 ksi). PFA is harder — 60 Shore D against 56 Shore D for FEP — which matters for wear surfaces and threads. PFA is stiffer (0.6 GPa vs 0.48 GPa) and PFA runs hotter in service (260°C vs 200°C continuous).
PFAChoose it when strength drives the design, or when surface hardness matters.
FEP vs PFA: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Flexural Strength
Shear Strength
Hardness, Shore A
Same in both: Poisson's Ratio 0.45
Physical
Density and transition temperatures.
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Same in both: Density 2.15 g/cm³0.08 lb/in³
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)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Max Service Temperature (short-term)
Vicat Softening Point (B50)
Same in both: Min Service Temperature -200°C-328 °F · Limiting Oxygen Index 95%
Electrical
Conductivity and insulation.
Dielectric Strength
Dissipation Factor (1 MHz)
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹⁶ Ω·m3.94×10²³ µΩ·in · Dielectric Constant (1 MHz) 2.1 · Volume Resistivity 1×10¹⁸ Ω·cm · 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.
Weldability
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Machinability 55 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Same in both: Embodied Carbon (primary production) 12 kg CO₂/kg · Embodied Water 300 L/kg35.9 gal/lb · 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 | PFA |
|---|---|---|
| Default condition | Unfilled | High Purity (Semiconductor) |
| Relative cost | $$$$$ Specialty | $$$$$ Specialty |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining, Sheet metal and Injection molding. Both take the same 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
FEP vs PFA — frequently asked
Is PFA stronger than FEP?
Yes. PFA has a typical yield strength of 14 MPa (2.03 ksi) against 13 MPa (1.89 ksi) for FEP — about 8% more. Tensile strength is 30 MPa (4.35 ksi) vs 23 MPa (3.34 ksi).
Which is cheaper, FEP or PFA?
Both sit in the same relative cost tier ($$$$$, specialty); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose FEP over PFA?
Pick PFA when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in FEP and PFA 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.