PTT GF15 vs PTT GF30
Polymer · PTT grade comparison
PTT GF15 and PTT GF30 are two grades of the same polymer grade, PTT: GF15 (15 % glass-fiber reinforced) versus GF30 (30 % glass-fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PTT GF30 is the stronger of the two: tensile strength 138 MPa (20 ksi) against 100 MPa (14.5 ksi) for PTT GF15, about 38% more. In exchange, PTT GF15 is the more ductile: elongation 3.5% versus 2.5% for PTT GF30. PTT GF15 is lighter (1.43 g/cm³ vs 1.55 g/cm³ for PTT GF30) and PTT GF30 is stiffer (9.5 GPa vs 5 GPa). On the shop floor, PTT GF15 machines more easily (good vs fair).
PTT GF15Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PTT GF30Choose it when strength drives the design, or when the part sees heat.
PTT GF15 vs PTT GF30: 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
Same in both: Shear Modulus 0.95 GPa0.14 Msi · Bulk Modulus 5 GPa0.65 Msi · Poisson's Ratio 0.4 · Yield Strength (0.2% offset) 58 MPa8.4 ksi · Compressive Strength 75 MPa10.9 ksi · Compressive Modulus 2.5 GPa0.36 Msi · Shear Strength 45 MPa6.5 ksi · Hardness, Shore D 78 Shore D · Hardness, Rockwell M 72 HRM · Hardness, Rockwell R 117 HRR
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 228°C442 °F · Glass Transition (Tg) 50°C122 °F · Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 0.4% · Refractive Index 1.6
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 1,350 J/kg·K0.32 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Vicat Softening Point (B50) 175°C347 °F · Limiting Oxygen Index 22% · Max Service Temperature (short-term) 140°C284 °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) 0.018 · 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 45 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Mold Shrinkage
Mold Temperature (typ.)
Same in both: Weldability 70 / 100 · Formability (cold) 50 / 100 · Polishability 60 / 100 · Melt Flow Rate 30 g/10 min · Processing Melt Temperature (typ.) 250°C482 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 70 MJ/kg30,095 BTU/lb · Embodied Carbon (primary production) 3 kg CO₂/kg · Embodied Water 130 L/kg15.6 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.
PTT GF15 vs PTT GF30 — frequently asked
Is PTT GF30 stronger than PTT GF15?
Yes. PTT GF30 has a typical tensile strength of 138 MPa (20 ksi) against 100 MPa (14.5 ksi) for PTT GF15 — about 38% more.
Which grade does FabDigit quote by default, GF15 or GF30?
UNF is the default PTT condition in the FabDigit quote flow (neither GF15 nor GF30). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, PTT GF15 or PTT GF30?
PTT GF15. Its machinability rates good (55/100) against fair (45/100) for PTT GF30.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PTT GF15 and PTT 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.