PTT GF30 vs PTT IM
Polymer · PTT grade comparison
PTT GF30 and PTT IM are two grades of the same polymer grade, PTT: GF30 (30 % glass-fiber reinforced) versus IM (impact-modified (toughened) PTT). The chemistry is identical, so every difference below comes from the condition. PTT GF30 is the stronger of the two: yield strength 58 MPa (8.41 ksi) against 40 MPa (5.8 ksi) for PTT IM, about 45% more; tensile strength follows at 138 MPa (20 ksi) vs 44 MPa (6.38 ksi). In exchange, PTT IM is the more ductile: elongation 150% versus 2.5% for PTT GF30, and PTT GF30 is harder (78 Shore D vs 68 Shore D). PTT IM is lighter (1.28 g/cm³ vs 1.55 g/cm³ for PTT GF30) and PTT GF30 is stiffer (9.5 GPa vs 1.9 GPa). On the shop floor, PTT IM machines more easily (good vs fair) and PTT GF30 welds better (very good vs good).
PTT GF30Choose it when strength drives the design, or when the part sees heat.
PTT IMChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PTT GF30 vs PTT IM: 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)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Same in both: Shear Modulus 0.95 GPa0.14 Msi · Bulk Modulus 5 GPa0.65 Msi · Poisson's Ratio 0.4 · Compressive Modulus 2.5 GPa0.36 Msi
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)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Same in both: Specific Heat Capacity 1,350 J/kg·K0.32 BTU/lb·°F · 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).
Corrosion Resistance
Same in both: UV / Weathering Resistance 45 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Mold Temperature (typ.)
Same in both: Polishability 60 / 100 · 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 GF30 vs PTT IM — frequently asked
Is PTT GF30 stronger than PTT IM?
Yes. PTT GF30 has a typical yield strength of 58 MPa (8.41 ksi) against 40 MPa (5.8 ksi) for PTT IM — about 45% more. Tensile strength is 138 MPa (20 ksi) vs 44 MPa (6.38 ksi).
Which grade does FabDigit quote by default, GF30 or IM?
UNF is the default PTT condition in the FabDigit quote flow (neither GF30 nor IM). 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 GF30 or PTT IM?
PTT IM. Its machinability rates good (58/100) against fair (45/100) for PTT GF30; for welding the order is PTT GF30 first (very good, 70/100) then PTT IM (good, 60/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PTT GF30 and PTT IM 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.