Materials / Compare
Aluminum vs. Steel AISI 1018
Compare Aluminum 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 (sheet, coil & plate datasheet); 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 stronger than Steel AISI 1018?
Steel AISI 1018 is stronger: its yield strength is 372 MPa against 276 MPa for Aluminum (35%).
Which is lighter, Aluminum or Steel AISI 1018?
Aluminum is lighter: 2,700 kg/m³ against 7,861 kg/m³ for Steel AISI 1018.
Which is stiffer, Aluminum or Steel AISI 1018?
Steel AISI 1018 is stiffer: Young's modulus 200 GPa against 68.3 GPa for Aluminum, so the same part in Steel AISI 1018 deflects less under the same load.
Which is lighter for the same job, Aluminum or Steel AISI 1018?
For the same stiffness or strength: Aluminum 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 | 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 or Steel AISI 1018?
Aluminum 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.