Materials / Compare
Aluminum 7075-T6 vs. Steel AISI 1045
Compare Aluminum 7075-T6 vs. Steel AISI 1045 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 | 531MPasourceproducer-stated, cold drawn |
| Ultimate tensile strength | 572MPasourcetypical | 627MPasourceproducer-stated, cold drawn |
| Elongation at break | 11%sourcetypical, in 4D | 12%sourcein 2 in (50.8 mm) |
| Young's modulus (stiffness) | 71GPasourcetypical | 210GPasourcetypical2.96x stiffer |
| Density | 2,800kg/m³sourcenominal | 7,800kg/m³sourcetypical |
| Strength to weight | 180kN·m/kg2.64x higher | 68.1kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg | 26.9MN·m/kg6% higher |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.3sourcetypical |
| Shear modulus | 26.7GPa | 80.8GPa3.03x stiffer in shear |
| Bulk modulus | 69.6GPa | 175GPa |
| Speed of sound | 5,036m/s | 5,189m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 40–45W/m·Ksourcetypical range, ambient |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 12µm/m·Ksourcetypical, mean 20-300 °C |
| 100 mm part over a 50 °C swing | 117µm growth | 60µm growth1.95x less |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 460–480J/kg·Ksourcetypical range, 50/100 °C |
| Heats up and cools (diffusivity) | 48.4mm²/s4.17x faster | 11.6mm²/s |
| Thermal shock resistance | 26,370W/m4.21x more resistant | 6,269W/m |
| Melting point | 532–635°Csourcemelting range | not sourced |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | AISI 1045 cold drawn bar (Niagara LaSalle) for mechanical; Ovako C45 (lists 'SAE 1045' as a similar designation) for physical constants |
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 Steel AISI 1045?
Steel AISI 1045 is stronger: its yield strength is 531 MPa against 503 MPa for Aluminum 7075-T6 (6%).
Which is lighter, Aluminum 7075-T6 or Steel AISI 1045?
Aluminum 7075-T6 is lighter: 2,800 kg/m³ against 7,800 kg/m³ for Steel AISI 1045.
Which is stiffer, Aluminum 7075-T6 or Steel AISI 1045?
Steel AISI 1045 is stiffer: Young's modulus 210 GPa against 71 GPa for Aluminum 7075-T6, so the same part in Steel AISI 1045 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Steel AISI 1045?
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; Steel AISI 1045 is lighter for a stiff rod or tie (tension).
| Part that must be | Aluminum 7075-T6 | Steel AISI 1045 |
|---|---|---|
| Stiff rod or tie (tension) | 6% heavier | lighter |
| Stiff beam (bending) | lighter | 1.62x heavier |
| Stiff panel or plate | lighter | 1.94x heavier |
| Strong rod or tie | lighter | 2.64x heavier |
| Strong beam | lighter | 2.69x heavier |
| Strong panel or plate | lighter | 2.71x 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 Steel AISI 1045?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 42.5 W/m·K for Steel AISI 1045.
Which expands less with temperature?
Steel AISI 1045 expands less: 12 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.