Materials / Compare
Aluminum 7075-T6 vs. Plastic PEEK
Compare Aluminum 7075-T6 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 | 503MPasourcetypical, 0.2% offset, .500 in dia specimen | 98MPasourcetypical, tensile yield |
| Ultimate tensile strength | 572MPasourcetypical | not sourced |
| Compressive strength | not sourced | 125MPasourcetypical, 23 C |
| Flexural strength | not sourced | 165MPasourcetypical, flexural stress at yield, 23 C |
| Elongation at break | 11%sourcetypical, in 4D | 25%sourcetypical, at break |
| Young's modulus (stiffness) | 71GPasourcetypical | 4GPasourcetypical (nominal) |
| Density | 2,800kg/m³sourcenominal | 1,300kg/m³sourcetypical (crystalline) |
| Strength to weight | 180kN·m/kg2.38x higher | 75.4kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg8.24x higher | 3.08MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.38sourcetypical |
| Shear modulus | 26.7GPa18.4x stiffer in shear | 1.45GPa |
| Bulk modulus | 69.6GPa | 5.56GPa |
| Speed of sound | 5,036m/s | 1,754m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 0.29W/m·Ksourcetypical, average, 23 C |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) |
| 100 mm part over a 50 °C swing | 117µm growth2.35x less | 275µm growth |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) |
| Heats up and cools (diffusivity) | 48.4mm²/s477x faster | 0.101mm²/s |
| Thermal shock resistance | 26,370W/m329x more resistant | 80.1W/m |
| Melting point | 532–635°Csourcemelting range | 343°Csourcetypical, DSC |
| Glass transition | not sourced | 143°Csourceonset (midpoint 150 C) |
| Max service temperature | not sourced | 240°CsourceUL 746B RTI, mechanical strength (continuous use index) |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | 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.
Questions
Is Aluminum 7075-T6 stronger than Plastic PEEK?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 98 MPa for Plastic PEEK (5.13x).
Which is lighter, Aluminum 7075-T6 or Plastic PEEK?
Plastic PEEK is lighter: 1,300 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.
Which is stiffer, Aluminum 7075-T6 or Plastic PEEK?
Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 4 GPa for Plastic PEEK, 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 PEEK?
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 PEEK |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 8.24x heavier |
| Stiff beam (bending) | lighter | 1.96x heavier |
| Stiff panel or plate | lighter | 21% heavier |
| Strong rod or tie | lighter | 2.38x heavier |
| Strong beam | lighter | 38% heavier |
| Strong panel or plate | lighter | 5% 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 PEEK?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 0.29 W/m·K for Plastic PEEK.
Which expands less with temperature?
Aluminum 7075-T6 expands less: 23.4 µm/m·K against 55 µm/m·K for Plastic PEEK.