Materials / Compare
Aluminum 7075-T6 vs. Plastic POM/Acetal
Compare Aluminum 7075-T6 vs. Plastic POM/Acetal 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 | 503MPasourcetypical, 0.2% offset, .500 in dia specimen | 69MPasourcetypical (single ASTM D638 tensile strength) |
| Ultimate tensile strength | 572MPasourcetypical8.29x stronger | 69MPasourcetypical |
| Compressive strength | not sourced | 124MPasourcecompressive stress at 10% deformation |
| Flexural strength | not sourced | 99MPasourceflexural yield strength, typical |
| Elongation at break | 11%sourcetypical, in 4D | 75%sourcetypical |
| Young's modulus (stiffness) | 71GPasourcetypical25.4x stiffer | 2.8GPasourcetypical |
| Density | 2,800kg/m³sourcenominal | 1,420kg/m³sourcetypical (DuPont product information for Delrin 100 NC010; 'The data listed here fall within the normal range of product properties') |
| Strength to weight | 180kN·m/kg3.7x higher | 48.6kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg12.9x higher | 1.97MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.35sourcetypical |
| Shear modulus | 26.7GPa25.7x stiffer in shear | 1.04GPa |
| Bulk modulus | 69.6GPa | 3.11GPa |
| Speed of sound | 5,036m/s | 1,404m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 0.4W/m·Ksourcetypical |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 122µm/m·Ksourcemean, 29 to 60 °C |
| 100 mm part over a 50 °C swing | 117µm growth5.21x less | 610µm growth |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 1,465J/kg·Ksourceaverage -18 to 100 °C, Delrin acetal resins (not grade-specific) |
| Heats up and cools (diffusivity) | 48.4mm²/s252x faster | 0.192mm²/s |
| Thermal shock resistance | 26,370W/m502x more resistant | 52.5W/m |
| Melting point | 532–635°Csourcemelting range | 175°Csourcecrystalline melting point |
| Max service temperature | not sourced | 125°CsourceHDT 1.8 MPa (annealed) |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | DuPont Delrin 100 acetal homopolymer, Table 2 'Typical Properties of Delrin Acetal Resins' (ASTM methods), Delrin Design Guide Module III hosted on delrin.com |
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 7075-T6 stronger than Plastic POM/Acetal?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 69 MPa for Plastic POM/Acetal (7.29x).
Which is lighter, Aluminum 7075-T6 or Plastic POM/Acetal?
Plastic POM/Acetal is lighter: 1,420 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.
Which is stiffer, Aluminum 7075-T6 or Plastic POM/Acetal?
Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 2.8 GPa for Plastic POM/Acetal, so the same part in Aluminum 7075-T6 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Plastic POM/Acetal?
For the same stiffness or strength: Aluminum 7075-T6 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 7075-T6 | Plastic POM/Acetal |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 12.9x heavier |
| Stiff beam (bending) | lighter | 2.55x heavier |
| Stiff panel or plate | lighter | 49% heavier |
| Strong rod or tie | lighter | 3.7x heavier |
| Strong beam | lighter | 1.91x heavier |
| Strong panel or plate | lighter | 37% 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 7075-T6 or Plastic POM/Acetal?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 0.4 W/m·K for Plastic POM/Acetal.
Which expands less with temperature?
Aluminum 7075-T6 expands less: 23.4 µm/m·K against 122 µm/m·K for Plastic POM/Acetal.