Materials / Compare
Plastic POM/Acetal vs. Rubber
Compare Plastic POM/Acetal vs. Rubber 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 | 69MPasourcetypical (single ASTM D638 tensile strength) | not given (tensile used) |
| Ultimate tensile strength | 69MPasourcetypical3x stronger | 23MPasourcetypical |
| Compressive strength | 124MPasourcecompressive stress at 10% deformation | not sourced |
| Flexural strength | 99MPasourceflexural yield strength, typical | not sourced |
| Elongation at break | 75%sourcetypical | 830%sourcetypical11.1x more ductile |
| Young's modulus (stiffness) | 2.8GPasourcetypical | not sourced |
| Density | 1,420kg/m³sourcetypical (DuPont product information for Delrin 100 NC010; 'The data listed here fall within the normal range of product properties') | 960kg/m³sourcetypical (specific gravity) |
| Strength to weight | 48.6kN·m/kg2.03x higher | 24kN·m/kg |
| Stiffness to weight | 1.97MN·m/kg | not sourced |
| Poisson's ratio | 0.35sourcetypical | 0.5sourcegovernment (NBS J. Res. 68A, 1964): computed by NBS for peroxide-cured gum NR vulcanizate, 25 °C, infinitesimal deformation0.49 in the solver: the linear element locks as the ratio nears 0.5 (nearly incompressible). |
| Shear modulus | 1.04GPa | not sourced |
| Bulk modulus | 3.11GPa | not sourced |
| Speed of sound | 1,404m/s | not sourced |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical | 0.151W/m·Ksourcegovernment selected value (US Army Natick Laboratories TR 66-49-PR, 1966), soft vulcanized natural rubber, 25 °C |
| Thermal expansion | 122µm/m·Ksourcemean, 29 to 60 °C | not sourced |
| 100 mm part over a 50 °C swing | 610µm growth | not sourced |
| Specific heat | 1,465J/kg·Ksourceaverage -18 to 100 °C, Delrin acetal resins (not grade-specific) | 1,881J/kg·Ksourcegovernment (NBS J. Res. 68A, Table 7; values observed for unvulcanized NR by Bekkedahl and Matheson), 25 °C |
| Heats up and cools (diffusivity) | 0.192mm²/s2.3x faster | 0.0836mm²/s |
| Thermal shock resistance | 52.5W/m | not sourced |
| Melting point | 175°Csourcecrystalline melting point | not sourced |
| Max service temperature | 125°CsourceHDT 1.8 MPa (annealed) | 70°Csourcecontinuous use operating range |
| Values for | DuPont Delrin 100 acetal homopolymer, Table 2 'Typical Properties of Delrin Acetal Resins' (ASTM methods), Delrin Design Guide Module III hosted on delrin.com | Weir Minerals Linatex Premium rubber (95 % natural rubber), typical physical properties, spec sheet WMD0118/202305 |
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 POM/Acetal stronger than Rubber?
Plastic POM/Acetal is stronger: its yield strength is 69 MPa against tensile strength 23 MPa for Rubber (3x).
Which is lighter, Plastic POM/Acetal or Rubber?
Rubber is lighter: 960 kg/m³ against 1,420 kg/m³ for Plastic POM/Acetal.
Which is lighter for the same job, Plastic POM/Acetal or Rubber?
For the same stiffness or strength: Plastic POM/Acetal is lighter for a strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic POM/Acetal | Rubber |
|---|---|---|
| Strong rod or tie | lighter | 2.03x heavier |
| Strong beam | lighter | 41% heavier |
| Strong panel or plate | lighter | 17% 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 is more ductile, Plastic POM/Acetal or Rubber?
Rubber stretches further before it breaks: 830% elongation at break against 75% for Plastic POM/Acetal.
Which conducts heat better, Plastic POM/Acetal or Rubber?
Plastic POM/Acetal conducts heat better: 0.4 W/m·K against 0.151 W/m·K for Rubber.