Materials / Compare
Plastic POM/Acetal vs. Plastic PTFE
Compare Plastic POM/Acetal vs. Plastic PTFE 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) | 9MPasourcetypical yield strength at 23 °C (Teflon PTFE, Table 8) |
| Ultimate tensile strength | 69MPasourcetypical | 39.3MPasourcetypical, skived tape 0.13 mm |
| Compressive strength | 124MPasourcecompressive stress at 10% deformation | not sourced |
| Flexural strength | 99MPasourceflexural yield strength, typical | not sourced |
| Elongation at break | 75%sourcetypical | 350%sourcetypical, skived tape 0.13 mm |
| 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') | 2,160kg/m³sourcetypical (standard specific gravity, ASTM D4894) |
| Strength to weight | 48.6kN·m/kg11.7x higher | 4.17kN·m/kg |
| Stiffness to weight | 1.97MN·m/kg | not sourced |
| Poisson's ratio | 0.35sourcetypical | 0.46sourcetypical, 23 °C (Teflon PTFE resins, Chemours handbook) |
| 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 | 0.25W/m·Ksourcetypical, granular resin, 4.6 mm specimen |
| Thermal expansion | 122µm/m·Ksourcemean, 29 to 60 °C | 100µm/m·Ksourcetypical, granular resin, 23-60 °C (ASTM E228) |
| 100 mm part over a 50 °C swing | 610µm growth | 500µm growth22% less |
| Specific heat | 1,465J/kg·Ksourceaverage -18 to 100 °C, Delrin acetal resins (not grade-specific) | 1,400J/kg·Ksourcetypical, granular resin, 20 °C (ASTM D4591) |
| Heats up and cools (diffusivity) | 0.192mm²/s2.33x faster | 0.0827mm²/s |
| Thermal shock resistance | 52.5W/m | not sourced |
| Melting point | 175°Csourcecrystalline melting point | 327°Csourcesecond melting peak (sintered polymer), +/-10 |
| Max service temperature | 125°CsourceHDT 1.8 MPa (annealed) | 260°Csourceservice temperature (Chemours general Teflon PTFE statement) |
| 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 | Chemours Teflon PTFE 7C X granular molding resin, typical values (tensile/elongation measured on 0.13 mm skived tape) |
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 Plastic PTFE?
Plastic POM/Acetal is stronger: its yield strength is 69 MPa against 9 MPa for Plastic PTFE (7.67x).
Which is lighter, Plastic POM/Acetal or Plastic PTFE?
Plastic POM/Acetal is lighter: 1,420 kg/m³ against 2,160 kg/m³ for Plastic PTFE.
Which is lighter for the same job, Plastic POM/Acetal or Plastic PTFE?
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 | Plastic PTFE |
|---|---|---|
| Strong rod or tie | lighter | 11.7x heavier |
| Strong beam | lighter | 5.91x heavier |
| Strong panel or plate | lighter | 4.21x 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 POM/Acetal or Plastic PTFE?
Plastic POM/Acetal conducts heat better: 0.4 W/m·K against 0.25 W/m·K for Plastic PTFE.
Which expands less with temperature?
Plastic PTFE expands less: 100 µm/m·K against 122 µm/m·K for Plastic POM/Acetal.