Materials / Compare
Aluminum ADC12 vs. Plastic PEEK
Compare Aluminum ADC12 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 | 149MPasourceone test result, 0.2% proof stress, as cast, ASTM tensile bar (Daiki) | 98MPasourcetypical, tensile yield |
| Ultimate tensile strength | 345MPasourceone test result, as cast, ASTM tensile bar (Daiki) | not sourced |
| Compressive strength | not sourced | 125MPasourcetypical, 23 C |
| Flexural strength | not sourced | 165MPasourcetypical, flexural stress at yield, 23 C |
| Elongation at break | 2.3%sourceone test result, as cast, ASTM tensile bar (Daiki) | 25%sourcetypical, at break |
| Young's modulus (stiffness) | 79.8GPasourcestandard value (S.S.Aluminum) | 4GPasourcetypical (nominal) |
| Density | 2,680kg/m³sourcemeasured (Daiki) | 1,300kg/m³sourcetypical (crystalline) |
| Strength to weight | 55.6kN·m/kg | 75.4kN·m/kg36% higher |
| Stiffness to weight | 29.8MN·m/kg9.68x higher | 3.08MN·m/kg |
| Poisson's ratio | not sourced | 0.38sourcetypical |
| Shear modulus | not sourced | 1.45GPa |
| Bulk modulus | not sourced | 5.56GPa |
| Speed of sound | 5,457m/s | 1,754m/s |
| Thermal | ||
| Thermal conductivity | 125W/m·Ksourcemeasured on specimens cut from a 50 x 100 x 5 mm flat die casting (Daiki) | 0.29W/m·Ksourcetypical, average, 23 C |
| Thermal expansion | 21µm/m·Ksourcemeasured, temperature range not stated (Daiki) | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) |
| 100 mm part over a 50 °C swing | 105µm growth2.62x less | 275µm growth |
| Specific heat | 911J/kg·Ksourcemeasured (Daiki) | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) |
| Heats up and cools (diffusivity) | 51.2mm²/s505x faster | 0.101mm²/s |
| Thermal shock resistance | not sourced | 80.1W/m |
| Melting point | 515–582°Csourcesolidus-liquidus (Daiki) | 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 | JIS ADC12 (Al-Si-Cu, about A383 / EN AC-46100) high-pressure die-casting alloy, as cast; physical properties from Daiki Aluminium Industry (ADC12 ingot producer) measured values; modulus from S.S.Aluminum (ADC12 ingot producer) standard values. | 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 ADC12 stronger than Plastic PEEK?
Aluminum ADC12 is stronger: its yield strength is 149 MPa against 98 MPa for Plastic PEEK (1.52x).
Which is lighter, Aluminum ADC12 or Plastic PEEK?
Plastic PEEK is lighter: 1,300 kg/m³ against 2,680 kg/m³ for Aluminum ADC12.
Which is stiffer, Aluminum ADC12 or Plastic PEEK?
Aluminum ADC12 is stiffer: Young's modulus 79.8 GPa against 4 GPa for Plastic PEEK, so the same part in Aluminum ADC12 deflects less under the same load.
Which is lighter for the same job, Aluminum ADC12 or Plastic PEEK?
For the same stiffness or strength: Aluminum ADC12 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate; Plastic PEEK is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Aluminum ADC12 | Plastic PEEK |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 9.68x heavier |
| Stiff beam (bending) | lighter | 2.17x heavier |
| Stiff panel or plate | lighter | 32% heavier |
| Strong rod or tie | 36% heavier | lighter |
| Strong beam | 1.56x heavier | lighter |
| Strong panel or plate | 1.67x 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, Aluminum ADC12 or Plastic PEEK?
Aluminum ADC12 conducts heat better: 125 W/m·K against 0.29 W/m·K for Plastic PEEK.
Which expands less with temperature?
Aluminum ADC12 expands less: 21 µm/m·K against 55 µm/m·K for Plastic PEEK.