PTMT GF30 vs PTMT GF40
Polymer · PTMT grade comparison
PTMT GF30 and PTMT GF40 are two grades of the same polymer grade, PTMT: GF30 (30 % glass-fiber reinforced) versus GF40 (40 % glass-fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PTMT GF40 is the stronger of the two: tensile strength 150 MPa (21.8 ksi) against 135 MPa (19.6 ksi) for PTMT GF30, about 11% more. In exchange, PTMT GF30 is the more ductile: elongation 2.8% versus 2.2% for PTMT GF40. PTMT GF30 is lighter (1.53 g/cm³ vs 1.61 g/cm³ for PTMT GF40) and PTMT GF40 is stiffer (12.5 GPa vs 9.5 GPa).
PTMT GF30Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PTMT GF40Choose it when strength drives the design.
PTMT GF30 vs PTMT 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
Shear Strength
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Shear Modulus 0.95 GPa0.14 Msi · Bulk Modulus 4 GPa0.58 Msi · Poisson's Ratio 0.4 · Yield Strength (0.2% offset) 55 MPa8 ksi · Compressive Strength 85 MPa12.3 ksi · Compressive Modulus 2.4 GPa0.35 Msi · Hardness, Shore D 82 Shore D · Hardness, Rockwell R 118 HRR
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 225°C437 °F · Glass Transition (Tg) 50°C122 °F · Water Absorption (24 h) 0.08% · Water Absorption (Saturation) 0.45% · Refractive Index 1.58
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Specific Heat Capacity 1,500 J/kg·K0.36 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 178°C352 °F · Limiting Oxygen Index 21% · Max Service Temperature (short-term) 160°C320 °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) 3.1 · Dissipation Factor (1 MHz) 0.018 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 78 / 100 · UV / Weathering Resistance 35 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Mold Shrinkage
Same in both: Weldability 70 / 100 · Formability (cold) 30 / 100 · Polishability 45 / 100 · Melt Flow Rate 25 g/10 min · Processing Melt Temperature (typ.) 255°C491 °F · Mold Temperature (typ.) 70°C158 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 95 MJ/kg40,843 BTU/lb · Embodied Carbon (primary production) 4.4 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.
PTMT GF30 vs PTMT GF40 — frequently asked
Is PTMT GF40 stronger than PTMT GF30?
Yes. PTMT GF40 has a typical tensile strength of 150 MPa (21.8 ksi) against 135 MPa (19.6 ksi) for PTMT 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, PTMT GF30 or PTMT GF40?
PTMT GF30, by a small margin. Both rate fair for machinability — 45/100 against 38/100 for PTMT GF40.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PTMT GF30 and PTMT 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.