PET CF30 vs PET FR
Polymer · PET grade comparison
PET CF30 and PET FR are two grades of the same polymer grade, PET: CF30 (30% Carbon Fiber) versus FR (flame-retardant UL 94 V-0 grade). The chemistry is identical, so every difference below comes from the condition. PET CF30 is the stronger of the two: tensile strength 200 MPa (29 ksi) against 135 MPa (19.6 ksi) for PET FR, about 48% more. PET CF30 is lighter (1.46 g/cm³ vs 1.69 g/cm³ for PET FR) and PET CF30 is stiffer (21 GPa vs 10.5 GPa). On the shop floor, PET FR welds better (fair vs poor) and PET FR forms better (fair vs not recommended).
PET CF30Choose it when strength drives the design, or when weight is the constraint.
PET FRChoose it when it will be welded.
PET CF30 vs PET FR: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Hardness, Rockwell M
Same in both: Shear Modulus 1.1 GPa0.16 Msi · Bulk Modulus 5 GPa0.65 Msi · Yield Strength (0.2% offset) 80 MPa11.6 ksi · Compressive Modulus 3 GPa0.44 Msi · Shear Strength 55 MPa8 ksi · Fracture Toughness (K_IC) 4 MPa·√m3.6 ksi·√in · Izod Impact, Notched 70 J/m1.3 ft·lbf/in · Hardness, Shore D 85 Shore D · Hardness, Rockwell R 120 HRR
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Water Absorption (24 h)
Water Absorption (Saturation)
Same in both: Glass Transition (Tg) 79°C174 °F · Refractive Index 1.575 · Light Transmission 88%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
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
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Vicat Softening Point (B50) 180°C356 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Volume Resistivity
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Dielectric Constant (1 MHz) 3.2 · Dissipation Factor (1 MHz) 0.018
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 70 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 120 L/kg14.4 gal/lb
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.
PET CF30 vs PET FR — frequently asked
Is PET CF30 stronger than PET FR?
Yes. PET CF30 has a typical tensile strength of 200 MPa (29 ksi) against 135 MPa (19.6 ksi) for PET FR — about 48% more.
Which grade does FabDigit quote by default, CF30 or FR?
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, PET CF30 or PET FR?
PET CF30, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for PET FR; for welding the order is PET FR first (fair, 45/100) then PET CF30 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PET CF30 and PET FR 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.