Materials / Compare
FDM Polycarbonate vs. Plastic PEEK
Compare FDM Polycarbonate vs. Plastic PEEK strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 53.3MPasourcetypical | 98MPasourcetypical, tensile yield |
| Ultimate tensile strength | 53.3MPasourcetypical, peak stress (= stress at yield) | not sourced |
| Compressive strength | not sourced | 125MPasourcetypical, 23 C |
| Flexural strength | 89.4MPasourcetypical | 165MPasourcetypical, flexural stress at yield, 23 C |
| Elongation at break | 9.2%sourcetypical | 25%sourcetypical, at break |
| Young's modulus (stiffness) | 2.39GPasourcetypical | 4GPasourcetypical (nominal) |
| Density | 1,180–1,200kg/m³sourcerange | 1,300kg/m³sourcetypical (crystalline) |
| Strength to weight | 44.8kN·m/kg | 75.4kN·m/kg1.68x higher |
| Stiffness to weight | 2.01MN·m/kg | 3.08MN·m/kg1.53x higher |
| Poisson's ratio | 0.38sourcebase material: polycarbonate family typical (Covestro Part and Mold Design guide, Table 3-1) | 0.38sourcetypical |
| Shear modulus | 0.867GPa | 1.45GPa1.67x stiffer in shear |
| Bulk modulus | 3.33GPa | 5.56GPa |
| Speed of sound | 1,418m/s | 1,754m/s |
| Thermal | ||
| Thermal conductivity | 0.2W/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, through-plane, 23 °C | 0.29W/m·Ksourcetypical, average, 23 C |
| Thermal expansion | 65µm/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, 23-55 °C, parallel | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) |
| 100 mm part over a 50 °C swing | 325µm growth | 275µm growth18% less |
| Specific heat | not sourced | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) |
| Heats up and cools (diffusivity) | not sourced | 0.101mm²/s |
| Thermal shock resistance | 42.5W/m | 80.1W/m1.89x more resistant |
| Melting point | not sourced | 343°Csourcetypical, DSC |
| Glass transition | 108°Csourcetypical | 143°Csourceonset (midpoint 150 C) |
| Max service temperature | 105°CsourceHDT 0.455 MPa (printed specimens) | 240°CsourceUL 746B RTI, mechanical strength (continuous use index) |
| Values for | Ultimaker PC, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 20, 2022. | Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07) |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
FDM Polycarbonate is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is FDM Polycarbonate stronger than Plastic PEEK?
Plastic PEEK is stronger: its yield strength is 98 MPa against 53.3 MPa for FDM Polycarbonate (1.84x).
Which is lighter, FDM Polycarbonate or Plastic PEEK?
FDM Polycarbonate is lighter: 1,190 kg/m³ against 1,300 kg/m³ for Plastic PEEK.
Which is stiffer, FDM Polycarbonate or Plastic PEEK?
Plastic PEEK is stiffer: Young's modulus 4 GPa against 2.39 GPa for FDM Polycarbonate, so the same part in Plastic PEEK deflects less under the same load.
Which is lighter for the same job, FDM Polycarbonate or Plastic PEEK?
For the same stiffness or strength: Plastic PEEK is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | FDM Polycarbonate | Plastic PEEK |
|---|---|---|
| Stiff rod or tie (tension) | 1.53x heavier | lighter |
| Stiff beam (bending) | 18% heavier | lighter |
| Stiff panel or plate | 9% heavier | lighter |
| Strong rod or tie | 1.68x heavier | lighter |
| Strong beam | 37% heavier | lighter |
| Strong panel or plate | 24% heavier | lighter |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, FDM Polycarbonate or Plastic PEEK?
Plastic PEEK conducts heat better: 0.29 W/m·K against 0.2 W/m·K for FDM Polycarbonate.
Which expands less with temperature?
Plastic PEEK expands less: 55 µm/m·K against 65 µm/m·K for FDM Polycarbonate.