PBT GF30 vs PBT GF40
Polymer · grade comparison
PBT-GF30 and PBT GF40 are both polymer grades, compared here in the GF40 condition. PBT GF40 is the stronger of the two: tensile strength 155 MPa (22.5 ksi) against 130 MPa (18.9 ksi) for PBT-GF30, about 19% more. In exchange, PBT-GF30 is the more ductile: elongation 3% versus 2.3% for PBT GF40. PBT-GF30 is lighter (1.53 g/cm³ vs 1.63 g/cm³ for PBT GF40) and PBT GF40 is stiffer (13 GPa vs 10 GPa). On the shop floor, PBT-GF30 machines more easily (good vs poor) and PBT GF40 welds better (very good vs fair).
PBT-GF30Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PBT GF40Choose it when strength drives the design, or when the part sees heat.
PBT-GF30 vs PBT 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
Shear Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Bulk Modulus
Yield Strength (0.2% offset)
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Same in both: Melting Temperature (Tm) 225°C437 °F
Thermal
How each material carries heat and how hot it can run.
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: Thermal Conductivity 0.25 W/m·K0.14 BTU/hr·ft·°F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dissipation Factor (1 MHz) 0.02 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 82 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: 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.
Manufacturing and finishing
| Capability | PBT-GF30 | PBT GF40 |
|---|---|---|
| Injection molding | — | Yes |
| Default condition | — | Unfilled |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Chrome Plating (Plastic) | — | Yes |
| EMI Shielding Coating | — | Yes |
| Soft Touch Coating | — | Yes |
| Spray Painting | — | Yes |
| UV Coating | — | Yes |
PBT-GF30 vs PBT GF40 — frequently asked
Is PBT GF40 stronger than PBT-GF30?
Yes. PBT GF40 has a typical tensile strength of 155 MPa (22.5 ksi) against 130 MPa (18.9 ksi) for PBT-GF30 — about 19% more.
Which is cheaper, PBT-GF30 or PBT GF40?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PBT-GF30 or PBT GF40?
PBT-GF30. Its machinability rates good (55/100) against poor (33/100) for PBT GF40; for welding the order is PBT GF40 first (very good, 70/100) then PBT-GF30 (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PBT-GF30 and PBT 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.