FabDigit

PTFE vs FEP and 2 more: properties

PTFEFEPPCTFEPFA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.5 GPa0.07 Msi
0.48 GPa0.07 Msi
1.5 GPa0.22 Msi
0.6 GPa0.09 Msi

Shear Modulus

0.18 GPa0.03 Msi
0.18 GPa0.03 Msi

Poisson's Ratio

0.46
0.45
0.42
0.45

Tensile Strength (Ultimate)

30 MPa4.4 ksi
23 MPa3.3 ksi
37 MPa5.4 ksi
30 MPa4.4 ksi

Yield Strength (0.2% offset)

12 MPa1.7 ksi
13 MPa1.9 ksi
34 MPa4.9 ksi
14 MPa2 ksi

Elongation at Break

350%
320%
110%
330%

Compressive Strength

15 MPa2.2 ksi
16 MPa2.3 ksi
40 MPa5.8 ksi
12 MPa1.7 ksi

Compressive Modulus

0.7 GPa0.1 Msi
1.4 GPa0.2 Msi

Flexural Strength

16 MPa2.3 ksi
60 MPa8.7 ksi
17 MPa2.5 ksi

Flexural Modulus

0.5 GPa0.07 Msi
0.6 GPa0.09 Msi
1.5 GPa0.22 Msi
0.62 GPa0.09 Msi

Shear Strength

15 MPa2.2 ksi
33 MPa4.8 ksi
17 MPa2.5 ksi

Izod Impact, Notched

160 J/m3 ft·lbf/in
2,700 J/m50.6 ft·lbf/in
145 J/m2.7 ft·lbf/in
1,300 J/m24.3 ft·lbf/in

Hardness, Shore A

98 Shore A
97 Shore A

Hardness, Shore D

56 Shore D
56 Shore D
78 Shore D
60 Shore D

Hardness, Rockwell R

58 HRR
25 HRR
112 HRR
50 HRR

Physical

Density and transition temperatures.

Density

2.17 g/cm³0.08 lb/in³
2.15 g/cm³0.08 lb/in³
2.12 g/cm³0.08 lb/in³
2.15 g/cm³0.08 lb/in³

Melting Temperature (Tm)

327°C621 °F
260°C500 °F
212°C414 °F
305°C581 °F

Glass Transition (Tg)

126°C259 °F
-90°C-130 °F
50°C122 °F
90°C194 °F

Water Absorption (24 h)

0.01%
0.01%
0.01%
0.02%

Water Absorption (Saturation)

0.01%
0.01%
0.01%
0.03%

Refractive Index

1.35
1.344
1.43
1.35

Light Transmission

95%
92%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.25 W/m·K0.14 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F
0.22 W/m·K0.13 BTU/hr·ft·°F
0.22 W/m·K0.13 BTU/hr·ft·°F

Specific Heat Capacity

1,000 J/kg·K0.24 BTU/lb·°F
1,170 J/kg·K0.28 BTU/lb·°F
900 J/kg·K0.21 BTU/lb·°F
1,100 J/kg·K0.26 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

130 µm/m·K72.2 µin/in·°F
100 µm/m·K55.6 µin/in·°F
65 µm/m·K36.1 µin/in·°F
130 µm/m·K72.2 µin/in·°F

Max Service Temperature (continuous)

260°C500 °F
200°C392 °F
135°C275 °F
260°C500 °F

Min Service Temperature

-200°C-328 °F
-200°C-328 °F
-240°C-400 °F
-200°C-328 °F

Heat Deflection Temp. @ 0.45 MPa

121°C250 °F
70°C158 °F
126°C259 °F
74°C165 °F

Heat Deflection Temp. @ 1.8 MPa

55°C131 °F
51°C124 °F
78°C172 °F
48°C118 °F

Max Service Temperature (short-term)

300°C572 °F
230°C446 °F
180°C356 °F
285°C545 °F

Vicat Softening Point (B50)

150°C302 °F
95°C203 °F

Same in both: Limiting Oxygen Index 95%

Electrical

Conductivity and insulation.

Dielectric Strength

30 kV/mm762 V/mil
24 kV/mm610 V/mil
21 kV/mm533 V/mil
25 kV/mm635 V/mil

Dielectric Constant (1 MHz)

2.1
2.1
2.5
2.1

Dissipation Factor (1 MHz)

2×10⁻⁴
6×10⁻⁴
0.014
2×10⁻⁴

Surface Resistivity

1×10¹⁷ Ω
1×10¹⁶ Ω
1×10¹⁶ Ω
1×10¹⁷ Ω

Same in both: Electrical Resistivity 1×10¹⁶ Ω·m3.94×10²³ µΩ·in · Volume Resistivity 1×10¹⁸ Ω·cm · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

98 / 100
98 / 100
95 / 100
100 / 100

UV / Weathering Resistance

95 / 100
98 / 100
92 / 100
99 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

80 / 100
55 / 100
70 / 100
55 / 100

Weldability

10 / 100
80 / 100
20 / 100
78 / 100

Formability (cold)

70 / 100
75 / 100
45 / 100
70 / 100

Polishability

20 / 100
45 / 100
55 / 100
45 / 100

Mold Shrinkage

4%
4%
1.8%
4.2%

Processing Melt Temperature (typ.)

375°C707 °F
350°C662 °F
290°C554 °F
370°C698 °F

Melt Flow Rate

7 g/10 min
5 g/10 min

Mold Temperature (typ.)

200°C392 °F
120°C248 °F
180°C356 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

210 MJ/kg90,284 BTU/lb
220 MJ/kg94,583 BTU/lb
240 MJ/kg103,182 BTU/lb
250 MJ/kg107,481 BTU/lb

Embodied Carbon (primary production)

9.5 kg CO₂/kg
12 kg CO₂/kg
13 kg CO₂/kg
12 kg CO₂/kg

Embodied Water

350 L/kg41.9 gal/lb
300 L/kg35.9 gal/lb
400 L/kg47.9 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

14 kN·m/kg
11 kN·m/kg
17 kN·m/kg
14 kN·m/kg

Specific Stiffness (E / density)

0.2 MN·m/kg
0.2 MN·m/kg
0.7 MN·m/kg
0.3 MN·m/kg

Modulus of Resilience

144 kJ/m³
176 kJ/m³
385 kJ/m³
163 kJ/m³

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scaleFEPPCTFEPFAPTFE

Manufacturing and finishing

CapabilityPTFEFEPPCTFEPFA
Default conditionVirginUnfilledUnfilledHigh Purity (Semiconductor)
Relative cost$$$ Premium$$$$$ Specialty$$$$$ Specialty$$$$$ Specialty
Min. machined wall0.5 mm0.5 mm0.5 mm0.5 mm
Best machined surfaceRa 0.8 µmRa 0.8 µmRa 0.8 µmRa 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.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PTFE and FEP 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.