PC GF20 vs PC GF40
Polymer · PC grade comparison
PC GF20 and PC GF40 are two grades of the same polymer grade, PC: GF20 (20% glass fiber reinforced) versus GF40 (40% Glass Fiber). The chemistry is identical, so every difference below comes from the condition. PC GF40 is the stronger of the two: tensile strength 150 MPa (21.8 ksi) against 100 MPa (14.5 ksi) for PC GF20, about 50% more. In exchange, PC GF20 is the more ductile: elongation 4% versus 2% for PC GF40. PC GF20 is lighter (1.34 g/cm³ vs 1.52 g/cm³ for PC GF40) and PC GF40 is stiffer (11.5 GPa vs 5.8 GPa). On the shop floor, PC GF20 welds better (very good vs poor).
PC GF20Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PC GF40Choose it when strength drives the design.
PC GF20 vs PC 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 0.83 GPa0.12 Msi · Bulk Modulus 4 GPa0.51 Msi · Poisson's Ratio 0.38 · Yield Strength (0.2% offset) 63 MPa9.1 ksi · Compressive Modulus 2.4 GPa0.35 Msi · Shear Strength 41 MPa5.9 ksi · Fracture Toughness (K_IC) 2.2 MPa·√m2 ksi·√in · Hardness, Shore D 84 Shore D · Hardness, Rockwell R 120 HRR
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Water Absorption (Saturation)
Same in both: Glass Transition (Tg) 147°C297 °F · Refractive Index 1.585 · Light Transmission 88%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Surface Resistivity 1×10¹⁵ Ω
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 55 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Melt Flow Rate 10 g/10 min
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: 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 GF20 vs PC GF40 — frequently asked
Is PC GF40 stronger than PC GF20?
Yes. PC GF40 has a typical tensile strength of 150 MPa (21.8 ksi) against 100 MPa (14.5 ksi) for PC GF20 — about 50% more.
Which grade does FabDigit quote by default, GF20 or GF40?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
Which is easier to machine, PC GF20 or PC GF40?
PC GF20, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for PC GF40; for welding the order is PC GF20 first (very good, 70/100) then PC GF40 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PC GF20 and PC 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.