Materials / Compare
Aluminum 7075-T6 vs. Iron
Compare Aluminum 7075-T6 vs. Iron 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 | 186MPasourcetypical (0.2% YS), hot rolled + SRA/recrystallization anneal |
| Ultimate tensile strength | 572MPasourcetypical | 290MPasourcetypical, SRA/recrystallization anneal |
| Elongation at break | 11%sourcetypical, in 4D | 38%sourcetypical, gauge 4D0 |
| Young's modulus (stiffness) | 71GPasourcetypical | 207GPasourcetypical, after SRA/recrystallization anneal |
| Density | 2,800kg/m³sourcenominal | 7,860kg/m³sourcetypical |
| Strength to weight | 180kN·m/kg7.59x higher | 23.7kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg | 26.3MN·m/kg4% higher |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.282sourceNIST critically evaluated best value (polycrystalline iron) |
| Shear modulus | 26.7GPa | 80.7GPa3.02x stiffer in shear |
| Bulk modulus | 69.6GPa | 158GPa |
| Speed of sound | 5,036m/s | 5,132m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 73.2W/m·Ksourcetypical at 20 °C |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 13.7µm/m·Ksourcemean, 20-399 °C |
| 100 mm part over a 50 °C swing | 117µm growth | 68.5µm growth1.71x less |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 450J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 48.4mm²/s2.34x faster | 20.7mm²/s |
| Thermal shock resistance | 26,370W/m7.65x more resistant | 3,447W/m |
| Melting point | 532–635°Csourcemelting range | 1,532°Csourcetypical |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | Cleveland-Cliffs / AK Steel ARMCO Pure Iron Product Data Bulletin (07/2022): Table 1 typical physical properties, Table 2 typical mechanical properties after SRA/recrystallization anneal. |
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 Iron?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 186 MPa for Iron (2.7x).
Which is lighter, Aluminum 7075-T6 or Iron?
Aluminum 7075-T6 is lighter: 2,800 kg/m³ against 7,860 kg/m³ for Iron.
Which is stiffer, Aluminum 7075-T6 or Iron?
Iron is stiffer: Young's modulus 207 GPa against 71 GPa for Aluminum 7075-T6, so the same part in Iron deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Iron?
For the same stiffness or strength: Aluminum 7075-T6 is lighter for a stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate; Iron is lighter for a stiff rod or tie (tension).
| Part that must be | Aluminum 7075-T6 | Iron |
|---|---|---|
| Stiff rod or tie (tension) | 4% heavier | lighter |
| Stiff beam (bending) | lighter | 1.64x heavier |
| Stiff panel or plate | lighter | 1.96x heavier |
| Strong rod or tie | lighter | 7.59x heavier |
| Strong beam | lighter | 5.45x heavier |
| Strong panel or plate | lighter | 4.62x 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 Iron?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 73.2 W/m·K for Iron.
Which expands less with temperature?
Iron expands less: 13.7 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.