Materials / Compare
Plastic PEEK vs. Solder SAC305
Compare Plastic PEEK vs. Solder SAC305 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 | 98MPasourcetypical, tensile yield | 22MPasourcetypical |
| Ultimate tensile strength | not sourced | 39.6MPasourcetypical |
| Compressive strength | 125MPasourcetypical, 23 C | not sourced |
| Flexural strength | 165MPasourcetypical, flexural stress at yield, 23 C | not sourced |
| Elongation at break | 25%sourcetypical, at break | 49%sourcetypical |
| Young's modulus (stiffness) | 4GPasourcetypical (nominal) | 6.9GPasourcetypical, temperature and strain rate not stated |
| Density | 1,300kg/m³sourcetypical (crystalline) | 7,350kg/m³sourcetypical |
| Strength to weight | 75.4kN·m/kg25.2x higher | 2.99kN·m/kg |
| Stiffness to weight | 3.08MN·m/kg3.28x higher | 0.939MN·m/kg |
| Poisson's ratio | 0.38sourcetypical | 0.35sourcetypical |
| Shear modulus | 1.45GPa | 2.56GPa1.76x stiffer in shear |
| Bulk modulus | 5.56GPa | 7.67GPa |
| Speed of sound | 1,754m/s | 969m/s |
| Thermal | ||
| Thermal conductivity | 0.29W/m·Ksourcetypical, average, 23 C | 61W/m·Ksourcetypical, temperature not stated |
| Thermal expansion | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) | 21.9µm/m·Ksourcemean, 20-100 °C (MacDermid Alpha) |
| 100 mm part over a 50 °C swing | 275µm growth | 110µm growth2.51x less |
| Specific heat | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) | 232J/kg·Ksourcetypical (MacDermid Alpha) |
| Heats up and cools (diffusivity) | 0.101mm²/s | 35.8mm²/s353x faster |
| Thermal shock resistance | 80.1W/m | 5,773W/m72.1x more resistant |
| Melting point | 343°Csourcetypical, DSC | 217–220°Csourcesolidus-liquidus |
| Glass transition | 143°Csourceonset (midpoint 150 C) | not sourced |
| Max service temperature | 240°CsourceUL 746B RTI, mechanical strength (continuous use index) | not sourced |
| Values for | Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07) | SAC305 (Sn96.5Ag3.0Cu0.5) solder alloy, bulk; Indium Corporation Indalloy 256 (SAC305) for Preforms product data sheet (Form No. 100346 R0, 2024), selected properties, test temperature not stated; expansion and specific heat from MacDermid Alpha VACULOY SAC TDS (06 September 2023). |
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 PEEK stronger than Solder SAC305?
Plastic PEEK is stronger: its yield strength is 98 MPa against 22 MPa for Solder SAC305 (4.45x).
Which is lighter, Plastic PEEK or Solder SAC305?
Plastic PEEK is lighter: 1,300 kg/m³ against 7,350 kg/m³ for Solder SAC305.
Which is stiffer, Plastic PEEK or Solder SAC305?
Solder SAC305 is stiffer: Young's modulus 6.9 GPa against 4 GPa for Plastic PEEK, so the same part in Solder SAC305 deflects less under the same load.
Which is lighter for the same job, Plastic PEEK or Solder SAC305?
For the same stiffness or strength: Plastic PEEK 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 PEEK | Solder SAC305 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 3.28x heavier |
| Stiff beam (bending) | lighter | 4.3x heavier |
| Stiff panel or plate | lighter | 4.71x heavier |
| Strong rod or tie | lighter | 25.2x heavier |
| Strong beam | lighter | 15.3x heavier |
| Strong panel or plate | lighter | 11.9x 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 PEEK or Solder SAC305?
Solder SAC305 conducts heat better: 61 W/m·K against 0.29 W/m·K for Plastic PEEK.
Which expands less with temperature?
Solder SAC305 expands less: 21.9 µm/m·K against 55 µm/m·K for Plastic PEEK.