Materials / Compare
Aluminum 7075-T6 vs. Stainless 303
Compare Aluminum 7075-T6 vs. Stainless 303 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 | 275MPasourceOutokumpu typical (product P = hot rolled plate, transverse) |
| Ultimate tensile strength | 572MPasourcetypical | 585MPasourceOutokumpu typical |
| Elongation at break | 11%sourcetypical, in 4D | 35%sourceOutokumpu typical, A5 |
| Young's modulus (stiffness) | 71GPasourcetypical | 200GPasourceat RT (Table 12) |
| Density | 2,800kg/m³sourcenominal | 7,900kg/m³sourceat RT |
| Strength to weight | 180kN·m/kg5.16x higher | 34.8kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg | 25.3MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | 26.7GPa | 76.9GPa2.88x stiffer in shear |
| Bulk modulus | 69.6GPa | 167GPa |
| Speed of sound | 5,036m/s | 5,032m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 15W/m·Ksourceat RT |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 16µm/m·Ksourcemean, 20–100 °C |
| 100 mm part over a 50 °C swing | 117µm growth | 80µm growth46% less |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 500J/kg·Ksourceat RT |
| Heats up and cools (diffusivity) | 48.4mm²/s12.7x faster | 3.8mm²/s |
| Thermal shock resistance | 26,370W/m29.2x more resistant | 902W/m |
| Melting point | 532–635°Csourcemelting range | not sourced |
| Max service temperature | not sourced | 871°Csourcecontinuous, scaling limit |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | 1.4305 / UNS S30300, Outokumpu typical values (hot rolled, solution annealed) from 'Steel Grades, Properties and Global Standards'; max service from Carpenter CarTech 303 datasheet |
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 303?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 275 MPa for Stainless 303 (1.83x).
Which is lighter, Aluminum 7075-T6 or Stainless 303?
Aluminum 7075-T6 is lighter: 2,800 kg/m³ against 7,900 kg/m³ for Stainless 303.
Which is stiffer, Aluminum 7075-T6 or Stainless 303?
Stainless 303 is stiffer: Young's modulus 200 GPa against 71 GPa for Aluminum 7075-T6, so the same part in Stainless 303 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Stainless 303?
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 | Stainless 303 |
|---|---|---|
| Stiff rod or tie (tension) | about equal | about equal |
| Stiff beam (bending) | lighter | 1.68x heavier |
| Stiff panel or plate | lighter | 2x heavier |
| Strong rod or tie | lighter | 5.16x heavier |
| Strong beam | lighter | 4.22x heavier |
| Strong panel or plate | lighter | 3.82x 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 303?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 15 W/m·K for Stainless 303.
Which expands less with temperature?
Stainless 303 expands less: 16 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.