Materials / Compare
Aluminum 7075-T6 vs. Stainless 304
Compare Aluminum 7075-T6 vs. Stainless 304 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 | 241MPasourcetypical, annealed, 70 °F (21 °C) |
| Ultimate tensile strength | 572MPasourcetypical | 586MPasourcetypical, annealed, 70 °F (21 °C) |
| Elongation at break | 11%sourcetypical, in 4D | 55%sourcetypical, annealed, in 2 in. (50.8 mm) |
| Young's modulus (stiffness) | 71GPasourcetypical | 193GPasourcetypical, in tension |
| Density | 2,800kg/m³sourcenominal | 8,030kg/m³sourcetypical |
| Strength to weight | 180kN·m/kg5.99x higher | 30kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg6% higher | 24MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | 26.7GPa | 74.2GPa2.78x stiffer in shear |
| Bulk modulus | 69.6GPa | 161GPa |
| Speed of sound | 5,036m/s | 4,903m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 16.2W/m·Ksourceat 100 °C |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 16.9µm/m·Ksourcemean, 0–100 °C |
| 100 mm part over a 50 °C swing | 117µm growth | 84.5µm growth38% less |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 500J/kg·Ksourcemean, 0–100 °C |
| Heats up and cools (diffusivity) | 48.4mm²/s12x faster | 4.03mm²/s |
| Thermal shock resistance | 26,370W/m31.5x more resistant | 838W/m |
| Melting point | 532–635°Csourcemelting range | 1,399–1,454°Csourcemelting range |
| Max service temperature | not sourced | 899°Csourcecontinuous, oxidation (scaling) limit in air |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | Type 304, annealed flat-rolled (Cleveland-Cliffs 304/304L Product Data Bulletin, May 2021); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual |
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 Stainless 304?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 241 MPa for Stainless 304 (2.09x).
Which is lighter, Aluminum 7075-T6 or Stainless 304?
Aluminum 7075-T6 is lighter: 2,800 kg/m³ against 8,030 kg/m³ for Stainless 304.
Which is stiffer, Aluminum 7075-T6 or Stainless 304?
Stainless 304 is stiffer: Young's modulus 193 GPa against 71 GPa for Aluminum 7075-T6, so the same part in Stainless 304 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Stainless 304?
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 | Stainless 304 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 6% heavier |
| Stiff beam (bending) | lighter | 1.74x heavier |
| Stiff panel or plate | lighter | 2.05x heavier |
| Strong rod or tie | lighter | 5.99x heavier |
| Strong beam | lighter | 4.68x heavier |
| Strong panel or plate | lighter | 4.14x 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 Stainless 304?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 16.2 W/m·K for Stainless 304.
Which expands less with temperature?
Stainless 304 expands less: 16.9 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.