PES GF30 vs PES GF40
Polymer · PES grade comparison
PES GF30 and PES GF40 are two grades of the same polymer grade, PES: GF30 (30 % glass-fibre reinforced) versus GF40 (40 % glass-fibre reinforced). The chemistry is identical, so every difference below comes from the condition. PES GF40 is the stronger of the two: tensile strength 155 MPa (22.5 ksi) against 140 MPa (20.3 ksi) for PES GF30, about 11% more. In exchange, PES GF30 is the more ductile: elongation 2.7% versus 2.2% for PES GF40. PES GF30 is lighter (1.6 g/cm³ vs 1.7 g/cm³ for PES GF40) and PES GF40 is stiffer (12.5 GPa vs 9.5 GPa). On the shop floor, PES GF40 welds better (very good vs good).
PES GF30Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PES GF40Choose it when strength drives the design, or when it will be welded.
PES GF30 vs PES 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
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Shear Modulus 0.95 GPa0.14 Msi · Bulk Modulus 4 GPa0.62 Msi · Poisson's Ratio 0.4 · Yield Strength (0.2% offset) 84 MPa12.2 ksi · Compressive Strength 100 MPa14.5 ksi · Compressive Modulus 2.6 GPa0.38 Msi · Shear Strength 62 MPa9 ksi · Fracture Toughness (K_IC) 2.6 MPa·√m2.4 ksi·√in · Hardness, Shore D 86 Shore D · Hardness, Rockwell R 122 HRR
Physical
Density and transition temperatures.
Density
Light Transmission
Same in both: Glass Transition (Tg) 225°C437 °F · Water Absorption (24 h) 0.43% · Water Absorption (Saturation) 2.1% · Refractive Index 1.65
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Specific Heat Capacity 1,100 J/kg·K0.26 BTU/lb·°F · Max Service Temperature (continuous) 180°C356 °F · Min Service Temperature -100°C-148 °F · Vicat Softening Point (B50) 222°C432 °F · Limiting Oxygen Index 38% · Max Service Temperature (short-term) 220°C428 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 16 kV/mm406 V/mil · Dielectric Constant (1 MHz) 3.5 · Dissipation Factor (1 MHz) 0.0035 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 150 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
Weldability
Mold Shrinkage
Same in both: Formability (cold) 55 / 100 · Polishability 70 / 100 · Melt Flow Rate 20 g/10 min · Processing Melt Temperature (typ.) 360°C680 °F · Mold Temperature (typ.) 150°C302 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 145 MJ/kg62,339 BTU/lb · Embodied Carbon (primary production) 8 kg CO₂/kg · Embodied Water 300 L/kg35.9 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.
PES GF30 vs PES GF40 — frequently asked
Is PES GF40 stronger than PES GF30?
Yes. PES GF40 has a typical tensile strength of 155 MPa (22.5 ksi) against 140 MPa (20.3 ksi) for PES GF30 — about 11% more.
Which grade does FabDigit quote by default, GF30 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, PES GF30 or PES GF40?
PES GF30, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for PES GF40; for welding the order is PES GF40 first (very good, 70/100) then PES GF30 (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PES GF30 and PES 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.