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PU-GF-Filled GF15 vs PU-GF-Filled GF40

Polyurethane · PU-GF-Filled grade comparison

PU-GF-Filled GF15 and PU-GF-Filled GF40 are two grades of the same polyurethane grade, PU-GF-Filled: GF15 (15 wt% short glass fibre filled) versus GF40 (40 wt% glass filled, high-stiffness grade). The chemistry is identical, so every difference below comes from the condition. PU-GF-Filled GF40 is the stronger of the two: tensile strength 68 MPa (9.86 ksi) against 55 MPa (7.98 ksi) for PU-GF-Filled GF15, about 24% more. In exchange, PU-GF-Filled GF15 is the more ductile: elongation 3.5% versus 1.5% for PU-GF-Filled GF40. PU-GF-Filled GF15 is lighter (1.42 g/cm³ vs 1.72 g/cm³ for PU-GF-Filled GF40) and PU-GF-Filled GF40 is stiffer (8 GPa vs 4 GPa). On the shop floor, PU-GF-Filled GF15 machines more easily (good vs fair).

PU-GF-Filled GF15Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PU-GF-Filled GF40Choose it when strength drives the design.

PU-GF-Filled GF15 vs PU-GF-Filled GF40: properties

PU-GF-Filled GF15PU-GF-Filled GF40

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

4 GPa0.58 Msi
8 GPa1.2 Msi

Tensile Strength (Ultimate)

55 MPa8 ksi
68 MPa9.9 ksi

Elongation at Break

3.5%
1.5%

Flexural Strength

85 MPa12.3 ksi
120 MPa17.4 ksi

Flexural Modulus

4 GPa0.58 Msi
8 GPa1.2 Msi

Izod Impact, Notched

35 J/m0.66 ft·lbf/in
22 J/m0.41 ft·lbf/in

Hardness, Shore D

85 Shore D
89 Shore D

Same in both: Poisson's Ratio 0.38 · Compressive Strength 110 MPa16 ksi · Compressive Modulus 5 GPa0.73 Msi · Hardness, Rockwell R 118 HRR

Physical

Density and transition temperatures.

Density

1.42 g/cm³0.05 lb/in³
1.72 g/cm³0.06 lb/in³

Same in both: Glass Transition (Tg) 95°C203 °F · Water Absorption (24 h) 0.2% · Water Absorption (Saturation) 1%

Thermal

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

Thermal Conductivity

0.35 W/m·K0.2 BTU/hr·ft·°F
0.45 W/m·K0.26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

50 µm/m·K27.8 µin/in·°F
35 µm/m·K19.4 µin/in·°F

Heat Deflection Temp. @ 0.45 MPa

105°C221 °F
122°C252 °F

Heat Deflection Temp. @ 1.8 MPa

84°C183 °F
98°C208 °F

Same in both: Specific Heat Capacity 1,300 J/kg·K0.31 BTU/lb·°F · Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -30°C-22 °F · Limiting Oxygen Index 21% · Max Service Temperature (short-term) 130°C266 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in · Dielectric Strength 18 kV/mm457 V/mil · Dielectric Constant (1 MHz) 4.5 · Dissipation Factor (1 MHz) 0.04 · Volume Resistivity 1×10¹³ Ω·cm · Surface Resistivity 1×10¹³ Ω · Comparative Tracking Index (CTI) 500 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 80 / 100 · UV / Weathering Resistance 25 / 100

Manufacturability

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

Machinability

65 / 100
50 / 100

Mold Shrinkage

0.18%
0.1%

Same in both: Weldability 5 / 100 · Formability (cold) 5 / 100 · Polishability 55 / 100 · Mold Temperature (typ.) 65°C149 °F

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 90 MJ/kg38,693 BTU/lb · Embodied Carbon (primary production) 5 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 0%

Strength versus weight

Yield strength against density for every polyurethane grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

71015203050701.11.21.31.4Density (g/cm³)Yield strength (MPa) — log scale

PU-GF-Filled GF15 vs PU-GF-Filled GF40 — frequently asked

Is PU-GF-Filled GF40 stronger than PU-GF-Filled GF15?

Yes. PU-GF-Filled GF40 has a typical tensile strength of 68 MPa (9.86 ksi) against 55 MPa (7.98 ksi) for PU-GF-Filled GF15 — about 24% more.

Which grade does FabDigit quote by default, GF15 or GF40?

GF30 is the default PU-GF-Filled condition in the FabDigit quote flow (neither GF15 nor GF40). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, PU-GF-Filled GF15 or PU-GF-Filled GF40?

PU-GF-Filled GF15. Its machinability rates good (65/100) against fair (50/100) for PU-GF-Filled GF40.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PU-GF-Filled GF15 and PU-GF-Filled GF40 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.