Materials / Compare
Plastic ABS (bulk/injection) vs. Iron
Compare Plastic ABS (bulk/injection) vs. Iron 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 | 45MPasourcetypical, tensile stress at yield 23 °C | 186MPasourcetypical (0.2% YS), hot rolled + SRA/recrystallization anneal |
| Ultimate tensile strength | not sourced | 290MPasourcetypical, SRA/recrystallization anneal |
| Flexural strength | 65MPasourcetypical, 23 °C | not sourced |
| Elongation at break | 10%sourcenominal strain at break, 23 °C | 38%sourcetypical, gauge 4D0 |
| Young's modulus (stiffness) | 2.3GPasourcetypical | 207GPasourcetypical, after SRA/recrystallization anneal |
| Density | 1,040kg/m³sourcetypical7.56x lighter | 7,860kg/m³sourcetypical |
| Strength to weight | 43.3kN·m/kg1.83x higher | 23.7kN·m/kg |
| Stiffness to weight | 2.21MN·m/kg | 26.3MN·m/kg11.9x higher |
| Poisson's ratio | 0.39sourcetypical, ABS family (Covestro Part and Mold Design guide, Table 3-1) | 0.282sourceNIST critically evaluated best value (polycrystalline iron) |
| Shear modulus | 0.827GPa | 80.7GPa97.6x stiffer in shear |
| Bulk modulus | 3.48GPa | 158GPa |
| Speed of sound | 1,487m/s | 5,132m/s |
| Thermal | ||
| Thermal conductivity | 0.17W/m·Ksourcetypical | 73.2W/m·Ksourcetypical at 20 °C |
| Thermal expansion | 80–110µm/m·Ksourcerange | 13.7µm/m·Ksourcemean, 20-399 °C |
| 100 mm part over a 50 °C swing | 475µm growth | 68.5µm growth6.93x less |
| Specific heat | not sourced | 450J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | not sourced | 20.7mm²/s |
| Thermal shock resistance | 21.4W/m | 3,447W/m161x more resistant |
| Melting point | not sourced | 1,532°Csourcetypical |
| Max service temperature | 94°CsourceHDT 1.8 MPa (annealed 4 h/80 °C) | not sourced |
| Values for | INEOS Styrolution Terluran GP-22 general-purpose injection-molding ABS, ISO typical values (TDS revision 08/01/2022) | Cleveland-Cliffs / AK Steel ARMCO Pure Iron Product Data Bulletin (07/2022): Table 1 typical physical properties, Table 2 typical mechanical properties after SRA/recrystallization anneal. |
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 Plastic ABS (bulk/injection) stronger than Iron?
Iron is stronger: its yield strength is 186 MPa against 45 MPa for Plastic ABS (bulk/injection) (4.13x).
Which is lighter, Plastic ABS (bulk/injection) or Iron?
Plastic ABS (bulk/injection) is lighter: 1,040 kg/m³ against 7,860 kg/m³ for Iron.
Which is stiffer, Plastic ABS (bulk/injection) or Iron?
Iron is stiffer: Young's modulus 207 GPa against 2.3 GPa for Plastic ABS (bulk/injection), so the same part in Iron deflects less under the same load.
Which is lighter for the same job, Plastic ABS (bulk/injection) or Iron?
For the same stiffness or strength: Plastic ABS (bulk/injection) is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate; Iron is lighter for a stiff rod or tie (tension), stiff beam (bending).
| Part that must be | Plastic ABS (bulk/injection) | Iron |
|---|---|---|
| Stiff rod or tie (tension) | 11.9x heavier | lighter |
| Stiff beam (bending) | 26% heavier | lighter |
| Stiff panel or plate | lighter | 1.69x heavier |
| Strong rod or tie | lighter | 1.83x heavier |
| Strong beam | lighter | 2.93x heavier |
| Strong panel or plate | lighter | 3.72x 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, Plastic ABS (bulk/injection) or Iron?
Iron conducts heat better: 73.2 W/m·K against 0.17 W/m·K for Plastic ABS (bulk/injection).
Which expands less with temperature?
Iron expands less: 13.7 µm/m·K against 95 µm/m·K for Plastic ABS (bulk/injection).