PC-GF GF20 vs PC-GF GF40
Polymer · PC-GF grade comparison
PC-GF GF20 and PC-GF GF40 are two grades of the same polymer grade, PC-GF: GF20 (20% glass fiber reinforced) versus GF40 (40% glass fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PC-GF GF40 is the stronger of the two: tensile strength 150 MPa (21.8 ksi) against 110 MPa (16 ksi) for PC-GF GF20, about 36% more. In exchange, PC-GF GF20 is the more ductile: elongation 3.5% versus 2% for PC-GF GF40. PC-GF GF20 is lighter (1.35 g/cm³ vs 1.52 g/cm³ for PC-GF GF40) and PC-GF GF40 is stiffer (11.5 GPa vs 6 GPa).
PC-GF GF20Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PC-GF GF40Choose it when strength drives the design.
PC-GF GF20 vs PC-GF GF40: 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
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Shear Modulus 3.1 GPa0.45 Msi · Bulk Modulus 10 GPa1.4 Msi · Poisson's Ratio 0.36 · Compressive Modulus 7 GPa1 Msi · Shear Strength 70 MPa10.2 ksi · Fracture Toughness (K_IC) 3 MPa·√m2.7 ksi·√in · Hardness, Rockwell R 119 HRR
Physical
Density and transition temperatures.
Density
Same in both: Glass Transition (Tg) 147°C297 °F · Water Absorption (24 h) 0.12% · Water Absorption (Saturation) 0.3%
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Thermal Conductivity 0.24 W/m·K0.14 BTU/hr·ft·°F · Specific Heat Capacity 1,150 J/kg·K0.27 BTU/lb·°F · Max Service Temperature (continuous) 130°C266 °F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 152°C306 °F · Limiting Oxygen Index 27% · Max Service Temperature (short-term) 160°C320 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Dielectric Strength 28 kV/mm711 V/mil · Dielectric Constant (1 MHz) 3.4 · Dissipation Factor (1 MHz) 0.009 · Volume Resistivity 1×10¹⁵ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 175 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 80 / 100 · UV / Weathering Resistance 30 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Mold Shrinkage
Melt Flow Rate
Same in both: Weldability 55 / 100 · Formability (cold) 10 / 100 · Polishability 30 / 100 · Processing Melt Temperature (typ.) 300°C572 °F · Mold Temperature (typ.) 100°C212 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 85 MJ/kg36,543 BTU/lb · Embodied Carbon (primary production) 5 kg CO₂/kg · Embodied Water 250 L/kg30 gal/lb · Typical Recycled Content 5%
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.
PC-GF GF20 vs PC-GF GF40 — frequently asked
Is PC-GF GF40 stronger than PC-GF GF20?
Yes. PC-GF GF40 has a typical tensile strength of 150 MPa (21.8 ksi) against 110 MPa (16 ksi) for PC-GF GF20 — about 36% more.
Which grade does FabDigit quote by default, GF20 or GF40?
GF30 is the default PC-GF condition in the FabDigit quote flow (neither GF20 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, PC-GF GF20 or PC-GF GF40?
PC-GF GF20, by a small margin. Both rate good for machinability — 64/100 against 55/100 for PC-GF GF40.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PC-GF GF20 and PC-GF 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.