Thermal conductivity against densityHigher and further left: spreads more heat for its weightThermal expansion against thermal conductivityLower and further right: warps less when heated
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Sources4 documents: Copper Development Association, Cleveland-Cliffs, Wieland, Steel Construction Institute
Copper C110
C11000 ETP copper, annealed to 0.050 mm grain size (OS050), 1 in. rod, copper.org typical values
Stainless Steel 304
Type 304, annealed flat-rolled (Cleveland-Cliffs 304/304L Product Data Bulletin, May 2021); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual
304/304L Stainless Steel Product Data Bulletin (2021)Cleveland-CliffsStainless Steel 304 · Yield strength: typical, annealed, 70 °F (21 °C)Stainless Steel 304 · Ultimate tensile strength: typical, annealed, 70 °F (21 °C)Stainless Steel 304 · Elongation at break: typical, annealed, in 2 in. (50.8 mm)Stainless Steel 304 · Young's modulus (stiffness): typical, in tensionStainless Steel 304 · Density: typicalStainless Steel 304 · Thermal conductivity: at 100 °CStainless Steel 304 · Thermal expansion: mean, 0–100 °CStainless Steel 304 · Specific heat: mean, 0–100 °CStainless Steel 304 · Melting point: melting rangeStainless Steel 304 · Max service temperature: continuous, oxidation (scaling) limit in air
3
Wieland-K32 (Cu-ETP, C11000) Data SheetWielandarchived copyCopper C110 · Poisson's ratio: reference value at room temperature (Wieland-K32 = Cu-ETP = C11000, rolled products)
4
Design Manual for Structural Stainless Steel, 4th Edition (P413)Steel Construction Institutearchived copyStainless Steel 304 · Poisson's ratio: design value (structural stainless steels)
Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Mechanical
Is Copper C110 stronger than Stainless Steel 304?
Stainless Steel 304 is stronger: its yield strength is 241 MPa against 69 MPa for Copper C110 (3.49x).
Which is lighter, Copper C110 or Stainless Steel 304?
Stainless Steel 304 is lighter: 8,030 kg/m³ against 8,913 kg/m³ for Copper C110.
Which is stiffer, Copper C110 or Stainless Steel 304?
Stainless Steel 304 is stiffer: Young's modulus 193 GPa against 117 GPa for Copper C110, so the same part in Stainless Steel 304 deflects less under the same load.
Which is lighter for the same job, Copper C110 or Stainless Steel 304?
For the same stiffness or strength: Stainless Steel 304 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
Copper C110
Stainless Steel 304
Stiff rod or tie (tension)
1.83x heavier
lighter
Stiff beam (bending)
42% heavier
lighter
Stiff panel or plate
31% heavier
lighter
Strong rod or tie
3.88x heavier
lighter
Strong beam
2.56x heavier
lighter
Strong panel or plate
2.07x 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).
Thermal
Which conducts heat better, Copper C110 or Stainless Steel 304?
Copper C110 conducts heat better: 391 W/m·K against 16.2 W/m·K for Stainless Steel 304.
Which expands less with temperature?
Copper C110 expands less: 16.9 µm/m·K against 16.9 µm/m·K for Stainless Steel 304.