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PC GF20 vs PC GF30

Polymer · PC grade comparison

PC GF20 and PC GF30 are two grades of the same polymer grade, PC: GF20 (20% glass fiber reinforced) versus GF30 (30% glass fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PC GF30 is the stronger of the two: tensile strength 125 MPa (18.1 ksi) against 100 MPa (14.5 ksi) for PC GF20, about 25% more. In exchange, PC GF20 is the more ductile: elongation 4% versus 3% for PC GF30. PC GF20 is lighter (1.34 g/cm³ vs 1.43 g/cm³ for PC GF30) and PC GF30 is stiffer (7.8 GPa vs 5.8 GPa).

PC GF20Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PC GF30Choose it when strength drives the design.

PC GF20 vs PC GF30: properties

PC GF20PC GF30

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

5.8 GPa0.84 Msi
7.8 GPa1.1 Msi

Tensile Strength (Ultimate)

100 MPa14.5 ksi
125 MPa18.1 ksi

Elongation at Break

4%
3%

Flexural Strength

145 MPa21 ksi
165 MPa23.9 ksi

Flexural Modulus

5.6 GPa0.81 Msi
7.5 GPa1.1 Msi

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 Strength 80 MPa11.6 ksi · Compressive Modulus 2.4 GPa0.35 Msi · Shear Strength 41 MPa5.9 ksi · Fracture Toughness (K_IC) 2.2 MPa·√m2 ksi·√in · Izod Impact, Notched 100 J/m1.9 ft·lbf/in · Hardness, Shore D 84 Shore D · Hardness, Rockwell M 70 HRM · Hardness, Rockwell R 120 HRR

Physical

Density and transition temperatures.

Density

1.34 g/cm³0.05 lb/in³
1.43 g/cm³0.05 lb/in³

Same in both: Glass Transition (Tg) 147°C297 °F · Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 0.35% · Refractive Index 1.585 · Light Transmission 88%

Thermal

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

Thermal Conductivity

0.22 W/m·K0.13 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

30 µm/m·K16.7 µin/in·°F
22 µm/m·K12.2 µin/in·°F

Max Service Temperature (continuous)

130°C266 °F
135°C275 °F

Heat Deflection Temp. @ 0.45 MPa

138°C280 °F
152°C306 °F

Heat Deflection Temp. @ 1.8 MPa

145°C293 °F
148°C298 °F

Same in both: Specific Heat Capacity 1,200 J/kg·K0.29 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 146°C295 °F · Limiting Oxygen Index 26% · Max Service Temperature (short-term) 145°C293 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 22 kV/mm559 V/mil · Dielectric Constant (1 MHz) 2.9 · Dissipation Factor (1 MHz) 0.01 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 250 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 55 / 100 · UV / Weathering Resistance 30 / 100

Manufacturability

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

Machinability

50 / 100
45 / 100

Polishability

85 / 100
40 / 100

Mold Shrinkage

0.3%
0.2%

Same in both: Weldability 70 / 100 · Formability (cold) 75 / 100 · Melt Flow Rate 10 g/10 min · Processing Melt Temperature (typ.) 295°C563 °F · Mold Temperature (typ.) 90°C194 °F

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 105 MJ/kg45,142 BTU/lb · Embodied Carbon (primary production) 6.3 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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePC

PC GF20 vs PC GF30 — frequently asked

Is PC GF30 stronger than PC GF20?

Yes. PC GF30 has a typical tensile strength of 125 MPa (18.1 ksi) against 100 MPa (14.5 ksi) for PC GF20 — about 25% more.

Which grade does FabDigit quote by default, GF20 or GF30?

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 GF30?

PC GF20, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for PC GF30.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PC GF20 and PC GF30 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.