Materials / Compare
Steel AISI 1018 vs. Plastic TPU
Compare Steel AISI 1018 vs. Plastic TPU 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 | 372MPasourceproducer-stated, cold drawn | not given (tensile used) |
| Ultimate tensile strength | 441MPasourceproducer-stated, cold drawn | 23.7MPasourcetypical, stress at break |
| Flexural strength | not sourced | 4.1MPasourcetypical |
| Elongation at break | 15%sourcein 2 in (50.8 mm) | not sourced |
| Young's modulus (stiffness) | 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) | 0.067GPasourcetypical |
| Density | 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) | 1,220kg/m³sourcetypical |
| Strength to weight | 47.3kN·m/kg2.44x higher | 19.4kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg463x higher | 0.0549MN·m/kg |
| Poisson's ratio | 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) | not sourced |
| Shear modulus | 75.7GPa | not sourced |
| Bulk modulus | 185GPa | not sourced |
| Speed of sound | 5,043m/s | 234m/s |
| Thermal | ||
| Thermal conductivity | 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) | not sourced |
| Thermal expansion | 12µm/m·Ksourcebase material: unalloyed carbon steel, Ovako family table (S275JR, 'none alloyed structural steels', C <= 0.21%); mean 20-300 °C | not sourced |
| 100 mm part over a 50 °C swing | 60µm growth | not sourced |
| Specific heat | 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) | not sourced |
| Heats up and cools (diffusivity) | 13.6mm²/s | not sourced |
| Thermal shock resistance | 5,473W/m | not sourced |
| Melting point | not sourced | 217°Csourcetypical |
| Max service temperature | not sourced | 50.3°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | AISI 1018 cold drawn bar (Niagara LaSalle, cold-finished bar producer) | Ultimaker TPU 95A, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 29, 2022. |
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.
Plastic TPU is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Steel AISI 1018 stronger than Plastic TPU?
Steel AISI 1018 is stronger: its yield strength is 372 MPa against tensile strength 23.7 MPa for Plastic TPU (15.7x).
Which is lighter, Steel AISI 1018 or Plastic TPU?
Plastic TPU is lighter: 1,220 kg/m³ against 7,861 kg/m³ for Steel AISI 1018.
Which is stiffer, Steel AISI 1018 or Plastic TPU?
Steel AISI 1018 is stiffer: Young's modulus 200 GPa against 0.067 GPa for Plastic TPU, so the same part in Steel AISI 1018 deflects less under the same load.
Which is lighter for the same job, Steel AISI 1018 or Plastic TPU?
For the same stiffness or strength: Steel AISI 1018 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie; Plastic TPU is lighter for a strong beam, strong panel or plate.
| Part that must be | Steel AISI 1018 | Plastic TPU |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 463x heavier |
| Stiff beam (bending) | lighter | 8.48x heavier |
| Stiff panel or plate | lighter | 2.23x heavier |
| Strong rod or tie | lighter | 2.44x heavier |
| Strong beam | 3% heavier | lighter |
| Strong panel or plate | 1.63x heavier | lighter |
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).