Materials / Compare
Plastic Polypropylene vs. Zinc Zamak 3
Compare Plastic Polypropylene vs. Zinc Zamak 3 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 | 33MPasourcetypical, tensile stress at yield ISO 527 | 221MPasourcetypical |
| Ultimate tensile strength | not sourced | 283MPasourcetypical |
| Elongation at break | not sourced | 10%sourcetypical, in 2 in. |
| Young's modulus (stiffness) | 1.45GPasourcetypical, tensile modulus ISO 527 | 85.5GPasourcetypical |
| Density | 900kg/m³sourcetypical, 23 °C ISO 1183-1 | 6,600kg/m³sourcetypical |
| Strength to weight | 36.7kN·m/kg10% higher | 33.5kN·m/kg |
| Stiffness to weight | 1.61MN·m/kg | 13MN·m/kg8.04x higher |
| Poisson's ratio | 0.42sourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) | 0.27sourcetypical, Zamak 3 hot-chamber die cast |
| Shear modulus | 0.511GPa | 33.7GPa65.9x stiffer in shear |
| Bulk modulus | 3.02GPa | 62GPa |
| Speed of sound | 1,269m/s | 3,599m/s |
| Thermal | ||
| Thermal conductivity | 0.17–0.22W/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) | 113W/m·Ksourcetypical |
| Thermal expansion | 80–100µm/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) | 27.4µm/m·Ksourcetypical |
| 100 mm part over a 50 °C swing | 450µm growth | 137µm growth3.28x less |
| Specific heat | not sourced | 419J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | not sourced | 40.9mm²/s |
| Thermal shock resistance | 28.6W/m | 7,782W/m272x more resistant |
| Melting point | not sourced | 381–387°Csourcemelting range |
| Max service temperature | 90°CsourceHDT 0.45 MPa (ISO 75B), unannealed | not sourced |
| Values for | LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO values | Zamak 3 (ASTM B86 die cast), Nathan Trotter (zinc alloy producer) technical data sheet, typical values |
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 Polypropylene stronger than Zinc Zamak 3?
Zinc Zamak 3 is stronger: its yield strength is 221 MPa against 33 MPa for Plastic Polypropylene (6.7x).
Which is lighter, Plastic Polypropylene or Zinc Zamak 3?
Plastic Polypropylene is lighter: 900 kg/m³ against 6,600 kg/m³ for Zinc Zamak 3.
Which is stiffer, Plastic Polypropylene or Zinc Zamak 3?
Zinc Zamak 3 is stiffer: Young's modulus 85.5 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Zinc Zamak 3 deflects less under the same load.
Which is lighter for the same job, Plastic Polypropylene or Zinc Zamak 3?
For the same stiffness or strength: Plastic Polypropylene is lighter for a stiff panel or plate, strong rod or tie, strong beam, strong panel or plate; Zinc Zamak 3 is lighter for a stiff rod or tie (tension), stiff beam (bending).
| Part that must be | Plastic Polypropylene | Zinc Zamak 3 |
|---|---|---|
| Stiff rod or tie (tension) | 8.04x heavier | lighter |
| Stiff beam (bending) | 5% heavier | lighter |
| Stiff panel or plate | lighter | 1.88x heavier |
| Strong rod or tie | lighter | 10% heavier |
| Strong beam | lighter | 2.06x heavier |
| Strong panel or plate | lighter | 2.83x 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 Polypropylene or Zinc Zamak 3?
Zinc Zamak 3 conducts heat better: 113 W/m·K against 0.195 W/m·K for Plastic Polypropylene.
Which expands less with temperature?
Zinc Zamak 3 expands less: 27.4 µm/m·K against 90 µm/m·K for Plastic Polypropylene.