Materials / Compare
Aluminum vs. Stainless 316
Compare Aluminum vs. Stainless 316 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 | 276MPasourcetypical, 0.2% offset, .500 in dia specimen | 265MPasourcetypical (representative), annealed 1.0 mm sheet |
| Ultimate tensile strength | 310MPasourcetypical | 583MPasourcetypical (representative), annealed 1.0 mm sheet |
| Elongation at break | 17%sourcetypical, in 4D, 0.500 in dia specimen | 61%sourcetypical (representative), annealed, in 2 in. (51 mm) |
| Young's modulus (stiffness) | 68.3GPasourcetypical | 200GPasourcetypical, in tension |
| Density | 2,700kg/m³sourcenominal | 8,027kg/m³sourcetypical |
| Strength to weight | 102kN·m/kg3.1x higher | 33kN·m/kg |
| Stiffness to weight | 25.3MN·m/kg2% higher | 24.9MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.3sourcedesign value (structural stainless steels) |
| Shear modulus | 25.7GPa | 76.9GPa3x stiffer in shear |
| Bulk modulus | 67GPa | 167GPa |
| Speed of sound | 5,030m/s | 4,992m/s |
| Thermal | ||
| Thermal conductivity | 167W/m·Ksourcetypical, 20 °C | 14.6W/m·Ksource20–100 °C |
| Thermal expansion | 23.6µm/m·Ksourcetypical, mean 20-100 °C | 16.5µm/m·Ksourcemean, 20–100 °C |
| 100 mm part over a 50 °C swing | 118µm growth | 82.5µm growth43% less |
| Specific heat | 896J/kg·Ksourcetypical, at 100 °C | 450J/kg·Ksourceat 20 °C |
| Heats up and cools (diffusivity) | 69mm²/s17.1x faster | 4.04mm²/s |
| Thermal shock resistance | 19,159W/m23.3x more resistant | 821W/m |
| Melting point | 582–652°Csourcesolidus-liquidus | 1,390–1,440°Csourcemelting range |
| Max service temperature | not sourced | 871–899°Csourceoxidation (scaling) limit in air |
| Values for | 6061-T6/T651, Kaiser Aluminum typical properties (sheet, coil & plate datasheet); Poisson from MIL-HDBK-5J | ATI 316 (UNS S31600), annealed 1.0 mm sheet, ATI technical data sheet (2012); 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 stronger than Stainless 316?
Aluminum is stronger: its yield strength is 276 MPa against 265 MPa for Stainless 316 (4%).
Which is lighter, Aluminum or Stainless 316?
Aluminum is lighter: 2,700 kg/m³ against 8,027 kg/m³ for Stainless 316.
Which is stiffer, Aluminum or Stainless 316?
Stainless 316 is stiffer: Young's modulus 200 GPa against 68.3 GPa for Aluminum, so the same part in Stainless 316 deflects less under the same load.
Which is lighter for the same job, Aluminum or Stainless 316?
For the same stiffness or strength: Aluminum 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 | Stainless 316 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 2% heavier |
| Stiff beam (bending) | lighter | 1.74x heavier |
| Stiff panel or plate | lighter | 2.08x heavier |
| Strong rod or tie | lighter | 3.1x heavier |
| Strong beam | lighter | 3.05x heavier |
| Strong panel or plate | lighter | 3.03x 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 or Stainless 316?
Aluminum conducts heat better: 167 W/m·K against 14.6 W/m·K for Stainless 316.
Which expands less with temperature?
Stainless 316 expands less: 16.5 µm/m·K against 23.6 µm/m·K for Aluminum.