Materials / Compare
Aluminum 7075-T6 vs. Plastic PETG
Compare Aluminum 7075-T6 vs. Plastic PETG 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 | 503MPasourcetypical, 0.2% offset, .500 in dia specimen | 46.2MPasourcetypical |
| Ultimate tensile strength | 572MPasourcetypical | 46.2MPasourcetypical, peak stress (= stress at yield) |
| Flexural strength | not sourced | 78.9MPasourcetypical |
| Elongation at break | 11%sourcetypical, in 4D | 7.6%sourcetypical |
| Young's modulus (stiffness) | 71GPasourcetypical36.6x stiffer | 1.94GPasourcetypical |
| Density | 2,800kg/m³sourcenominal | 1,270kg/m³sourcetypical |
| Strength to weight | 180kN·m/kg4.94x higher | 36.4kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg16.6x higher | 1.53MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | not sourced |
| Shear modulus | 26.7GPa | not sourced |
| Bulk modulus | 69.6GPa | not sourced |
| Speed of sound | 5,036m/s | 1,236m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| 100 mm part over a 50 °C swing | 117µm growth2.18x less | 255µm growth |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed) |
| Heats up and cools (diffusivity) | 48.4mm²/s380x faster | 0.127mm²/s |
| Thermal shock resistance | 26,370W/m | not sourced |
| Melting point | 532–635°Csourcemelting range | not sourced |
| Glass transition | not sourced | 77.4°Csourcetypical |
| Max service temperature | not sourced | 76.2°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | Ultimaker PETG, 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 v1.00, April 29, 2022. |
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.
Plastic PETG is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Aluminum 7075-T6 stronger than Plastic PETG?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 46.2 MPa for Plastic PETG (10.9x).
Which is lighter, Aluminum 7075-T6 or Plastic PETG?
Plastic PETG is lighter: 1,270 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.
Which is stiffer, Aluminum 7075-T6 or Plastic PETG?
Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 1.94 GPa for Plastic PETG, so the same part in Aluminum 7075-T6 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Plastic PETG?
For the same stiffness or strength: Aluminum 7075-T6 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 | Aluminum 7075-T6 | Plastic PETG |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 16.6x heavier |
| Stiff beam (bending) | lighter | 2.74x heavier |
| Stiff panel or plate | lighter | 1.51x heavier |
| Strong rod or tie | lighter | 4.94x heavier |
| Strong beam | lighter | 2.23x heavier |
| Strong panel or plate | lighter | 50% heavier |
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, Aluminum 7075-T6 or Plastic PETG?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 0.21 W/m·K for Plastic PETG.
Which expands less with temperature?
Aluminum 7075-T6 expands less: 23.4 µm/m·K against 51 µm/m·K for Plastic PETG.