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PCT GF15 vs PCT GF40

Polymer · PCT grade comparison

PCT GF15 and PCT GF40 are two grades of the same polymer grade, PCT: GF15 (15 % glass-fiber reinforced) versus GF40 (40 % glass-fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PCT GF40 is the stronger of the two: tensile strength 150 MPa (21.8 ksi) against 95 MPa (13.8 ksi) for PCT GF15, about 58% more. In exchange, PCT GF15 is the more ductile: elongation 3.5% versus 1.8% for PCT GF40. PCT GF15 is lighter (1.35 g/cm³ vs 1.58 g/cm³ for PCT GF40) and PCT GF40 is stiffer (12.5 GPa vs 5.8 GPa). On the shop floor, PCT GF15 machines more easily (45 vs 35 out of 100).

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

PCT GF40Choose it when strength drives the design, or when the part sees heat.

PCT GF15 vs PCT GF40: properties

PCT GF15PCT GF40

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

5.8 GPa0.84 Msi
12.5 GPa1.8 Msi

Tensile Strength (Ultimate)

95 MPa13.8 ksi
150 MPa21.8 ksi

Elongation at Break

3.5%
1.8%

Flexural Strength

145 MPa21 ksi
225 MPa32.6 ksi

Flexural Modulus

5.5 GPa0.8 Msi
12 GPa1.7 Msi

Izod Impact, Notched

55 J/m1 ft·lbf/in
100 J/m1.9 ft·lbf/in

Same in both: Poisson's Ratio 0.4 · Yield Strength (0.2% offset) 52 MPa7.5 ksi · Compressive Strength 75 MPa10.9 ksi · Hardness, Rockwell R 118 HRR

Physical

Density and transition temperatures.

Density

1.35 g/cm³0.05 lb/in³
1.58 g/cm³0.06 lb/in³

Same in both: Melting Temperature (Tm) 288°C550 °F · Glass Transition (Tg) 90°C194 °F · Water Absorption (24 h) 0.09% · Water Absorption (Saturation) 0.35% · Refractive Index 1.56

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

40 µm/m·K22.2 µin/in·°F
18 µm/m·K10 µin/in·°F

Max Service Temperature (continuous)

140°C284 °F
155°C311 °F

Heat Deflection Temp. @ 0.45 MPa

265°C509 °F
190°C374 °F

Heat Deflection Temp. @ 1.8 MPa

240°C464 °F
262°C504 °F

Same in both: Thermal Conductivity 0.22 W/m·K0.13 BTU/hr·ft·°F · Specific Heat Capacity 1,250 J/kg·K0.3 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 240°C464 °F · Limiting Oxygen Index 23% · Max Service Temperature (short-term) 260°C500 °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) 3.2 · Dissipation Factor (1 MHz) 0.015 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁶ Ω · Comparative Tracking Index (CTI) 250 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 70 / 100 · UV / Weathering Resistance 55 / 100

Manufacturability

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

Machinability

45 / 100
35 / 100

Mold Shrinkage

0.6%
0.25%

Same in both: Weldability 60 / 100 · Formability (cold) 30 / 100 · Polishability 50 / 100 · Melt Flow Rate 20 g/10 min · Processing Melt Temperature (typ.) 310°C590 °F · Mold Temperature (typ.) 120°C248 °F

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 100 MJ/kg42,992 BTU/lb · Embodied Carbon (primary production) 4.6 kg CO₂/kg · Embodied Water 180 L/kg21.6 gal/lb · Typical Recycled Content 0%

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 scalePCT

PCT GF15 vs PCT GF40 — frequently asked

Is PCT GF40 stronger than PCT GF15?

Yes. PCT GF40 has a typical tensile strength of 150 MPa (21.8 ksi) against 95 MPa (13.8 ksi) for PCT GF15 — about 58% more.

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

PCT GF15, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for PCT GF40.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PCT GF15 and PCT 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.