Materials / Compare
Aluminum 6061-T6 vs. Steel AISI 1018
Compare Aluminum 6061-T6 vs. Steel AISI 1018 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 | 372MPasourceproducer-stated, cold drawn |
| Ultimate tensile strength | 310MPasourcetypical | 441MPasourceproducer-stated, cold drawn |
| Elongation at break | 17%sourcetypical, in 4D, 0.500 in dia specimen | 15%sourcein 2 in (50.8 mm) |
| Young's modulus (stiffness) | 68.3GPasourcetypical | 200GPasourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Density | 2,700kg/m³sourcenominal | 7,861kg/m³sourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Strength to weight | 102kN·m/kg2.16x higher | 47.3kN·m/kg |
| Stiffness to weight | 25.3MN·m/kg | 25.4MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.32sourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Shear modulus | 25.7GPa | 75.7GPa2.95x stiffer in shear |
| Bulk modulus | 67GPa | 185GPa |
| Speed of sound | 5,030m/s | 5,043m/s |
| Thermal | ||
| Thermal conductivity | 167W/m·Ksourcetypical, 20 °C | 51.9W/m·Ksourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Thermal expansion | 23.6µm/m·Ksourcetypical, mean 20-100 °C | 12µm/m·Ksourcebase material: unalloyed carbon steel, Ovako family table (S275JR, 'none alloyed structural steels', C <= 0.21%); mean 20-300 °C |
| 100 mm part over a 50 °C swing | 118µm growth | 60µm growth1.97x less |
| Specific heat | 896J/kg·Ksourcetypical, at 100 °C | 486J/kg·Ksourcebase material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018) |
| Heats up and cools (diffusivity) | 69mm²/s5.08x faster | 13.6mm²/s |
| Thermal shock resistance | 19,159W/m3.5x more resistant | 5,473W/m |
| Melting point | 582–652°Csourcesolidus-liquidus | not sourced |
| Values for | 6061-T6/T651, Kaiser Aluminum typical properties; Poisson from MIL-HDBK-5J | AISI 1018 cold drawn bar (Niagara LaSalle, cold-finished bar producer) |
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 6061-T6 stronger than Steel AISI 1018?
Steel AISI 1018 is stronger: its yield strength is 372 MPa against 276 MPa for Aluminum 6061-T6 (35%).
Which is lighter, Aluminum 6061-T6 or Steel AISI 1018?
Aluminum 6061-T6 is lighter: 2,700 kg/m³ against 7,861 kg/m³ for Steel AISI 1018.
Which is stiffer, Aluminum 6061-T6 or Steel AISI 1018?
Steel AISI 1018 is stiffer: Young's modulus 200 GPa against 68.3 GPa for Aluminum 6061-T6, so the same part in Steel AISI 1018 deflects less under the same load.
Which is lighter for the same job, Aluminum 6061-T6 or Steel AISI 1018?
For the same stiffness or strength: Aluminum 6061-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 6061-T6 | Steel AISI 1018 |
|---|---|---|
| Stiff rod or tie (tension) | about equal | about equal |
| Stiff beam (bending) | lighter | 1.7x heavier |
| Stiff panel or plate | lighter | 2.04x heavier |
| Strong rod or tie | lighter | 2.16x heavier |
| Strong beam | lighter | 2.39x heavier |
| Strong panel or plate | lighter | 2.51x 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 6061-T6 or Steel AISI 1018?
Aluminum 6061-T6 conducts heat better: 167 W/m·K against 51.9 W/m·K for Steel AISI 1018.
Which expands less with temperature?
Steel AISI 1018 expands less: 12 µm/m·K against 23.6 µm/m·K for Aluminum 6061-T6.