Materials / Compare
Plastic POM/Acetal vs. Titanium
Compare Plastic POM/Acetal vs. Titanium 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) | 885MPasourcetypical, plate (>0.187 in), annealed, 0.2% offset |
| Ultimate tensile strength | 69MPasourcetypical | 940MPasourcetypical, plate, annealed |
| Compressive strength | 124MPasourcecompressive stress at 10% deformation | not sourced |
| Flexural strength | 99MPasourceflexural yield strength, typical | not sourced |
| Elongation at break | 75%sourcetypical | 16%sourcetypical, in 2 in., plate annealed |
| Young's modulus (stiffness) | 2.8GPasourcetypical | 107–122GPasourcetypical range, 20 °C |
| Density | 1,420kg/m³sourcetypical (DuPont product information for Delrin 100 NC010; 'The data listed here fall within the normal range of product properties') | 4,430kg/m³sourcenominal |
| Strength to weight | 48.6kN·m/kg | 200kN·m/kg4.11x higher |
| Stiffness to weight | 1.97MN·m/kg | 25.8MN·m/kg13.1x higher |
| Poisson's ratio | 0.35sourcetypical | 0.342sourcemean of TIMET measurements |
| Shear modulus | 1.04GPa | 42.7GPa41.1x stiffer in shear |
| Bulk modulus | 3.11GPa | 121GPa |
| Speed of sound | 1,404m/s | 5,084m/s |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical | 6.6W/m·Ksourcetypical, 20 °C, mill annealed |
| Thermal expansion | 122µm/m·Ksourcemean, 29 to 60 °C | 9µm/m·Ksourcetypical, mean 0-100 °C |
| 100 mm part over a 50 °C swing | 610µm growth | 45µm growth13.6x less |
| Specific heat | 1,465J/kg·Ksourceaverage -18 to 100 °C, Delrin acetal resins (not grade-specific) | 580J/kg·Ksourcetypical, 20 °C |
| Heats up and cools (diffusivity) | 0.192mm²/s | 2.57mm²/s13.4x faster |
| Thermal shock resistance | 52.5W/m | 3,730W/m71x more resistant |
| Melting point | 175°Csourcecrystalline melting point | 1,630–1,650°Csourcemelting range |
| Max service temperature | 125°CsourceHDT 1.8 MPa (annealed) | 400°Csourceupper recommended use temperature |
| 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 | TIMETAL 6-4 (Ti-6Al-4V Grade 5) annealed plate typical (TIMET properties manual) + TIMET datasheet TMC-0150 physical properties |
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 Titanium?
Titanium is stronger: its yield strength is 885 MPa against 69 MPa for Plastic POM/Acetal (12.8x).
Which is lighter, Plastic POM/Acetal or Titanium?
Plastic POM/Acetal is lighter: 1,420 kg/m³ against 4,430 kg/m³ for Titanium.
Which is stiffer, Plastic POM/Acetal or Titanium?
Titanium is stiffer: Young's modulus 115 GPa against 2.8 GPa for Plastic POM/Acetal, so the same part in Titanium deflects less under the same load.
Which is lighter for the same job, Plastic POM/Acetal or Titanium?
For the same stiffness or strength: Titanium 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 | Plastic POM/Acetal | Titanium |
|---|---|---|
| Stiff rod or tie (tension) | 13.1x heavier | lighter |
| Stiff beam (bending) | 2.05x heavier | lighter |
| Stiff panel or plate | 10% heavier | lighter |
| Strong rod or tie | 4.11x heavier | lighter |
| Strong beam | 1.76x heavier | lighter |
| Strong panel or plate | 15% 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).
Which conducts heat better, Plastic POM/Acetal or Titanium?
Titanium conducts heat better: 6.6 W/m·K against 0.4 W/m·K for Plastic POM/Acetal.
Which expands less with temperature?
Titanium expands less: 9 µm/m·K against 122 µm/m·K for Plastic POM/Acetal.