FabDigit

PEI vs PC and 2 more: properties

PEIPCPMMAPOM

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.2 GPa0.46 Msi
2.4 GPa0.34 Msi
3.2 GPa0.46 Msi
2.8 GPa0.41 Msi

Shear Modulus

1.2 GPa0.17 Msi
0.83 GPa0.12 Msi
1.2 GPa0.17 Msi
1.1 GPa0.15 Msi

Bulk Modulus

4 GPa0.55 Msi
4 GPa0.51 Msi
6 GPa0.81 Msi
3 GPa0.45 Msi

Poisson's Ratio

0.36
0.38
0.37
0.35

Tensile Strength (Ultimate)

105 MPa15.2 ksi
68 MPa9.9 ksi
70 MPa10.2 ksi
63 MPa9.1 ksi

Yield Strength (0.2% offset)

105 MPa15.2 ksi
63 MPa9.1 ksi
68 MPa9.9 ksi
62 MPa9 ksi

Elongation at Break

60%
110%
4.5%
30%

Compressive Strength

140 MPa20.3 ksi
80 MPa11.6 ksi
110 MPa16 ksi
105 MPa15.2 ksi

Compressive Modulus

3 GPa0.44 Msi
2.4 GPa0.35 Msi
3.1 GPa0.45 Msi
2.7 GPa0.39 Msi

Flexural Strength

150 MPa21.8 ksi
97 MPa14.1 ksi
100 MPa14.5 ksi
90 MPa13.1 ksi

Flexural Modulus

3.3 GPa0.48 Msi
2.4 GPa0.34 Msi
3.1 GPa0.45 Msi
2.6 GPa0.38 Msi

Shear Strength

85 MPa12.3 ksi
41 MPa5.9 ksi
60 MPa8.7 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

3 MPa·√m2.7 ksi·√in
2.2 MPa·√m2 ksi·√in
1.2 MPa·√m1.1 ksi·√in
4 MPa·√m3.6 ksi·√in

Izod Impact, Notched

53 J/m0.99 ft·lbf/in
800 J/m15 ft·lbf/in
18 J/m0.34 ft·lbf/in
70 J/m1.3 ft·lbf/in

Hardness, Shore D

87 Shore D
84 Shore D
89 Shore D
81 Shore D

Hardness, Rockwell M

109 HRM
70 HRM
92 HRM
80 HRM

Hardness, Rockwell R

125 HRR
120 HRR
120 HRR

Physical

Density and transition temperatures.

Density

1.27 g/cm³0.05 lb/in³
1.2 g/cm³0.04 lb/in³
1.19 g/cm³0.04 lb/in³
1.41 g/cm³0.05 lb/in³

Glass Transition (Tg)

217°C423 °F
147°C297 °F
105°C221 °F
-60°C-76 °F

Water Absorption (24 h)

0.25%
0.15%
0.3%
0.22%

Water Absorption (Saturation)

1.25%
0.35%
2%
0.8%

Refractive Index

1.66
1.585
1.491

Light Transmission

78%
88%
92%

Melting Temperature (Tm)

166°C331 °F

Thermal

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

Thermal Conductivity

0.22 W/m·K0.13 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F
0.19 W/m·K0.11 BTU/hr·ft·°F
0.31 W/m·K0.18 BTU/hr·ft·°F

Specific Heat Capacity

1,100 J/kg·K0.26 BTU/lb·°F
1,200 J/kg·K0.29 BTU/lb·°F
1,470 J/kg·K0.35 BTU/lb·°F
1,470 J/kg·K0.35 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

55 µm/m·K30.6 µin/in·°F
67 µm/m·K37.2 µin/in·°F
70 µm/m·K38.9 µin/in·°F
110 µm/m·K61.1 µin/in·°F

Max Service Temperature (continuous)

170°C338 °F
120°C248 °F
70°C158 °F
95°C203 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F
-40°C-40 °F
-40°C-40 °F

Heat Deflection Temp. @ 0.45 MPa

210°C410 °F
138°C280 °F
96°C205 °F
158°C316 °F

Heat Deflection Temp. @ 1.8 MPa

200°C392 °F
129°C264 °F
88°C190 °F
104°C219 °F

Vicat Softening Point (B50)

219°C426 °F
146°C295 °F
105°C221 °F
160°C320 °F

Limiting Oxygen Index

47%
26%
18%
15%

Max Service Temperature (short-term)

200°C392 °F
145°C293 °F
95°C203 °F
140°C284 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁵ Ω·m3.94×10²² µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Strength

33 kV/mm838 V/mil
22 kV/mm559 V/mil
25 kV/mm635 V/mil
20 kV/mm508 V/mil

Dielectric Constant (1 MHz)

3.15
2.9
2.7
3.7

Dissipation Factor (1 MHz)

0.0013
0.01
0.02
0.005

Volume Resistivity

1×10¹⁷ Ω·cm
1×10¹⁶ Ω·cm
1×10¹⁵ Ω·cm
1×10¹⁴ Ω·cm

Surface Resistivity

1×10¹⁶ Ω
1×10¹⁵ Ω
1×10¹⁵ Ω
1×10¹⁴ Ω

Comparative Tracking Index (CTI)

175 V
250 V
600 V
600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
55 / 100
80 / 100
70 / 100

UV / Weathering Resistance

40 / 100
30 / 100
92 / 100
30 / 100

Manufacturability

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

Machinability

65 / 100
65 / 100
70 / 100
88 / 100

Weldability

60 / 100
70 / 100
55 / 100
55 / 100

Formability (cold)

45 / 100
75 / 100
45 / 100
40 / 100

Polishability

70 / 100
85 / 100
96 / 100
70 / 100

Mold Shrinkage

0.6%
0.6%
0.5%
2%

Melt Flow Rate

9 g/10 min
10 g/10 min
2 g/10 min
9 g/10 min

Processing Melt Temperature (typ.)

370°C698 °F
295°C563 °F
240°C464 °F
200°C392 °F

Mold Temperature (typ.)

150°C302 °F
90°C194 °F
70°C158 °F
85°C185 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

230 MJ/kg98,882 BTU/lb
105 MJ/kg45,142 BTU/lb
101 MJ/kg43,422 BTU/lb
100 MJ/kg42,992 BTU/lb

Embodied Carbon (primary production)

9 kg CO₂/kg
6.3 kg CO₂/kg
6.4 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
250 L/kg30 gal/lb
280 L/kg33.6 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

0%
5%
2%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

83 kN·m/kg
57 kN·m/kg
59 kN·m/kg
45 kN·m/kg

Specific Stiffness (E / density)

2.5 MN·m/kg
2 MN·m/kg
2.7 MN·m/kg
2 MN·m/kg

Modulus of Resilience

1,723 kJ/m³
844 kJ/m³
723 kJ/m³
686 kJ/m³

Thermal Diffusivity

0.2 mm²/s
0.1 mm²/s
0.1 mm²/s
0.1 mm²/s

Same in both: 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 scalePCPEIPMMAPOM

Manufacturing and finishing

CapabilityPEIPCPMMAPOM
CNC machiningYesYesYes
Sheet metalYesYesYes
3D printingYesYes
Default conditionUnfilled (1000)UnfilledExtrudedUnfilled
Relative cost$$$$$ Specialty$ Budget$ Budget$$ Standard
Min. machined wall0.5 mm0.5 mm0.5 mm
Best machined surfaceRa 0.8 µmRa 0.8 µmRa 0.8 µm
Conductive CoatingYesYes
Dyeing (Nylon)YesYes
PaintingYesYesYes
Primer CoatingYesYes
Tinted CoatingYesYes
Vacuum MetallizationYesYes
Waterproof CoatingYesYes

Both are offered for Injection molding. They share 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PEI and PC 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.