FabDigit

PU Cast vs TPU and 2 more: properties

PU CastTPUPU FoamPoron

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0 GPa2.9×10⁻⁴ Msi
0.03 GPa0 Msi
2×10⁻⁴ GPa2.9×10⁻⁵ Msi
0 GPa2.18×10⁻⁴ Msi

Shear Modulus

7×10⁻⁴ GPa1.02×10⁻⁴ Msi

Bulk Modulus

2 GPa0.29 Msi

Poisson's Ratio

0.49
0.48
0.3
0.3

Tensile Strength (Ultimate)

12 MPa1.7 ksi
40 MPa5.8 ksi
0.13 MPa0.02 ksi
1 MPa0.15 ksi

Elongation at Break

700%
550%
150%
150%

Compressive Strength

1 MPa0.15 ksi
0.01 MPa7.25×10⁻⁴ ksi
0.07 MPa0.01 ksi

Shear Strength

5 MPa0.73 ksi

Hardness, Shore A

40 Shore A
85 Shore A
20 Shore A

Hardness, Shore D

10 Shore D
33 Shore D

Tear Strength

20 kN/m114 lbf/in
70 kN/m400 lbf/in
0.3 kN/m1.7 lbf/in
2 kN/m8.6 lbf/in

Compression Set (22 h, 70 °C)

15%
35%
5%
5%

Compressive Modulus

8×10⁻⁴ GPa1.16×10⁻⁴ Msi

Physical

Density and transition temperatures.

Density

1.1 g/cm³0.04 lb/in³
1.18 g/cm³0.04 lb/in³
0.03 g/cm³0 lb/in³
0.32 g/cm³0.01 lb/in³

Glass Transition (Tg)

-50°C-58 °F
-40°C-40 °F
-50°C-58 °F
-35°C-31 °F

Water Absorption (24 h)

0.5%
0.8%
3%

Water Absorption (Saturation)

1.5%
1.8%
800%

Refractive Index

1.5
1.51

Melting Temperature (Tm)

185°C365 °F

Thermal

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

Thermal Conductivity

0.18 W/m·K0.1 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F
0.06 W/m·K0.03 BTU/hr·ft·°F

Specific Heat Capacity

1,800 J/kg·K0.43 BTU/lb·°F
1,700 J/kg·K0.41 BTU/lb·°F
1,500 J/kg·K0.36 BTU/lb·°F
1,700 J/kg·K0.41 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

200 µm/m·K111 µin/in·°F
170 µm/m·K94.4 µin/in·°F
70 µm/m·K38.9 µin/in·°F

Max Service Temperature (continuous)

80°C176 °F
80°C176 °F
90°C194 °F
90°C194 °F

Limiting Oxygen Index

21%
22%
19%

Vicat Softening Point (B50)

72°C162 °F

Same in both: Min Service Temperature -40°C-40 °F · Max Service Temperature (short-term) 120°C248 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
1×10⁹ Ω·m3.94×10¹⁶ µΩ·in
1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in

Dielectric Strength

20 kV/mm508 V/mil
25 kV/mm635 V/mil

Dielectric Constant (1 MHz)

5
5
1.1
1.7

Dissipation Factor (1 MHz)

0.05
0.05

Volume Resistivity

1×10¹³ Ω·cm
1×10¹¹ Ω·cm
1×10¹² Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹² Ω

Comparative Tracking Index (CTI)

600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

78 / 100
78 / 100
70 / 100

UV / Weathering Resistance

35 / 100
40 / 100
25 / 100
40 / 100

Manufacturability

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

Machinability

25 / 100
25 / 100
90 / 100
80 / 100

Weldability

15 / 100
85 / 100
30 / 100

Formability (cold)

85 / 100
90 / 100
90 / 100
90 / 100

Polishability

25 / 100
40 / 100
5 / 100

Mold Shrinkage

1.5%
1.2%
1.5%

Processing Melt Temperature (typ.)

80°C176 °F
210°C410 °F

Mold Temperature (typ.)

100°C212 °F
30°C86 °F
50°C122 °F

Melt Flow Rate

25 g/10 min

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

102 MJ/kg43,852 BTU/lb
105 MJ/kg45,142 BTU/lb
102 MJ/kg43,852 BTU/lb
100 MJ/kg42,992 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
5.2 kg CO₂/kg
4.6 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

210 L/kg25.2 gal/lb
250 L/kg30 gal/lb
220 L/kg26.4 gal/lb

Typical Recycled Content

0%
2%
10%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

11 kN·m/kg
34 kN·m/kg
4 kN·m/kg
3 kN·m/kg

Thermal Diffusivity

0.1 mm²/s
0.1 mm²/s
0.8 mm²/s
0.1 mm²/s

Same in both: Specific Stiffness (E / density) 0 MN·m/kg

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 scaleTPUPU CastPU FoamPoron

Manufacturing and finishing

CapabilityPU CastTPUPU FoamPoron
CNC machiningYes
Sheet metalYes
3D printingYes
Default conditionShore A 40Shore A 85Open CellStandard
Relative cost$$ Standard$$ Standard$ Budget$$ Standard
Min. machined wall0.5 mm
Best machined surfaceRa 0.8 µm
Conductive CoatingYes
Dyeing (Nylon)Yes
PaintingYes
Primer CoatingYes
Tinted CoatingYes
Vacuum MetallizationYes
Waterproof CoatingYes

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 PU Cast and TPU 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.