Materials / Compare
Brass C360 vs. Plastic PEEK
Compare Brass C360 vs. Plastic PEEK 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 | 310MPasourcetypical, 0.5% extension under load | 98MPasourcetypical, tensile yield |
| Ultimate tensile strength | 400MPasourcetypical | not sourced |
| Compressive strength | not sourced | 125MPasourcetypical, 23 C |
| Flexural strength | not sourced | 165MPasourcetypical, flexural stress at yield, 23 C |
| Elongation at break | 25%sourcetypical, 1 in. rod | 25%sourcetypical, at break |
| Young's modulus (stiffness) | 96.5GPasourcetypical, temper-independent | 4GPasourcetypical (nominal) |
| Density | 8,498kg/m³sourcenominal | 1,300kg/m³sourcetypical (crystalline) |
| Strength to weight | 36.5kN·m/kg | 75.4kN·m/kg2.07x higher |
| Stiffness to weight | 11.4MN·m/kg3.69x higher | 3.08MN·m/kg |
| Poisson's ratio | 0.34sourcebase material: leaded free-machining brass CuZn39Pb2 (C37700), Wieland-Z30 rolled products, reference value at room temperature | 0.38sourcetypical |
| Shear modulus | 36GPa24.8x stiffer in shear | 1.45GPa |
| Bulk modulus | 101GPa | 5.56GPa |
| Speed of sound | 3,370m/s | 1,754m/s |
| Thermal | ||
| Thermal conductivity | 116W/m·Ksourcetypical, 20 °C | 0.29W/m·Ksourcetypical, average, 23 C |
| Thermal expansion | 20.5µm/m·Ksourcetypical, mean 20-300 °C | 55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C) |
| 100 mm part over a 50 °C swing | 103µm growth2.68x less | 275µm growth |
| Specific heat | 377J/kg·Ksourcetypical, 20 °C | 2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012) |
| Heats up and cools (diffusivity) | 36.2mm²/s357x faster | 0.101mm²/s |
| Thermal shock resistance | 11,997W/m150x more resistant | 80.1W/m |
| Melting point | 888–899°Csourcesolidus-liquidus | 343°Csourcetypical, DSC |
| Glass transition | not sourced | 143°Csourceonset (midpoint 150 C) |
| Max service temperature | not sourced | 240°CsourceUL 746B RTI, mechanical strength (continuous use index) |
| Values for | C36000 free-cutting brass, H02 half-hard rod 1 in. section (20% cold work), copper.org typical values | Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07) |
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 Brass C360 stronger than Plastic PEEK?
Brass C360 is stronger: its yield strength is 310 MPa against 98 MPa for Plastic PEEK (3.16x).
Which is lighter, Brass C360 or Plastic PEEK?
Plastic PEEK is lighter: 1,300 kg/m³ against 8,498 kg/m³ for Brass C360.
Which is stiffer, Brass C360 or Plastic PEEK?
Brass C360 is stiffer: Young's modulus 96.5 GPa against 4 GPa for Plastic PEEK, so the same part in Brass C360 deflects less under the same load.
Which is lighter for the same job, Brass C360 or Plastic PEEK?
For the same stiffness or strength: Brass C360 is lighter for a stiff rod or tie (tension); Plastic PEEK is lighter for a stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Brass C360 | Plastic PEEK |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 3.69x heavier |
| Stiff beam (bending) | 33% heavier | lighter |
| Stiff panel or plate | 2.26x heavier | lighter |
| Strong rod or tie | 2.07x heavier | lighter |
| Strong beam | 3.03x heavier | lighter |
| Strong panel or plate | 3.68x 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, Brass C360 or Plastic PEEK?
Brass C360 conducts heat better: 116 W/m·K against 0.29 W/m·K for Plastic PEEK.
Which expands less with temperature?
Brass C360 expands less: 20.5 µm/m·K against 55 µm/m·K for Plastic PEEK.