Materials / Compare
Aluminum 7075-T6 vs. Steel
Compare Aluminum 7075-T6 vs. Steel 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 | 385MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISC |
| Ultimate tensile strength | 572MPasourcetypical | 505MPasourcetypical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey) |
| Elongation at break | 11%sourcetypical, in 4D | not sourced |
| Young's modulus (stiffness) | 71GPasourcetypical | 200GPasourcedesign value (AISC 360-16) |
| Density | 2,800kg/m³sourcenominal | 7,850kg/m³sourcenominal (constructional data) |
| Strength to weight | 180kN·m/kg3.66x higher | 49kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg | 25.5MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.3sourcedesign value (AISC 360-16 Commentary) |
| Shear modulus | 26.7GPa | 76.9GPa2.88x stiffer in shear |
| Bulk modulus | 69.6GPa | 167GPa |
| Speed of sound | 5,036m/s | 5,048m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 48W/m·Ksourcenominal at 20 °C |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 12µm/m·Ksourcenominal (constructional data, no temperature range stated) |
| 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·Ksourcebase material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °C |
| Heats up and cools (diffusivity) | 48.4mm²/s3.72x faster | 13mm²/s |
| Thermal shock resistance | 26,370W/m4.89x more resistant | 5,390W/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 | Generic structural steel, cited as ASTM A992 (the current US structural grade): ASTM A992 W-shapes; Fy/Fu specified minimums from AISC publications (AISC 360-16 Commentary; Modern Steel Construction); elastic constants AISC 360; physical constants from the bauforumstahl structural-steel EPD, which names A992 among covered product standards. |
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?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 385 MPa for Steel (31%).
Which is lighter, Aluminum 7075-T6 or Steel?
Aluminum 7075-T6 is lighter: 2,800 kg/m³ against 7,850 kg/m³ for Steel.
Which is stiffer, Aluminum 7075-T6 or Steel?
Steel is stiffer: Young's modulus 200 GPa against 71 GPa for Aluminum 7075-T6, so the same part in Steel deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Steel?
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.
| Part that must be | Aluminum 7075-T6 | Steel |
|---|---|---|
| Stiff rod or tie (tension) | about equal | about equal |
| Stiff beam (bending) | lighter | 1.67x heavier |
| Stiff panel or plate | lighter | 1.99x heavier |
| Strong rod or tie | lighter | 3.66x heavier |
| Strong beam | lighter | 3.35x heavier |
| Strong panel or plate | lighter | 3.2x 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?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 48 W/m·K for Steel.
Which expands less with temperature?
Steel expands less: 12 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.