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: Cleveland-Cliffs, Nathan Trotter, Steel Construction Institute, Eastern Alloys
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
Zinc Zamak 3
Zamak 3 (ASTM B86 die cast), Nathan Trotter (zinc alloy producer) technical data sheet, typical values
1
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
Design Manual for Structural Stainless Steel, 4th Edition (P413)Steel Construction Institutearchived copyStainless Steel 304 · Poisson's ratio: design value (structural stainless steels)
4
Zinc Die Casting Properties Guide (2012)Eastern AlloysZinc Zamak 3 · Poisson's ratio: typical, Zamak 3 hot-chamber die cast
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 Stainless Steel 304 stronger than Zinc Zamak 3?
Stainless Steel 304 is stronger: its yield strength is 241 MPa against 221 MPa for Zinc Zamak 3 (9%).
Which is lighter, Stainless Steel 304 or Zinc Zamak 3?
Zinc Zamak 3 is lighter: 6,600 kg/m³ against 8,030 kg/m³ for Stainless Steel 304.
Which is stiffer, Stainless Steel 304 or Zinc Zamak 3?
Stainless Steel 304 is stiffer: Young's modulus 193 GPa against 85.5 GPa for Zinc Zamak 3, so the same part in Stainless Steel 304 deflects less under the same load.
Which is lighter for the same job, Stainless Steel 304 or Zinc Zamak 3?
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; Zinc Zamak 3 is lighter for a strong rod or tie, strong beam, strong panel or plate.
Part that must be
Stainless Steel 304
Zinc Zamak 3
Stiff rod or tie (tension)
lighter
1.86x heavier
Stiff beam (bending)
lighter
23% heavier
Stiff panel or plate
lighter
8% heavier
Strong rod or tie
12% heavier
lighter
Strong beam
15% heavier
lighter
Strong panel or plate
17% 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 is more ductile, Stainless Steel 304 or Zinc Zamak 3?
Stainless Steel 304 stretches further before it breaks: 55% elongation at break against 10% for Zinc Zamak 3.
Thermal
Which conducts heat better, Stainless Steel 304 or Zinc Zamak 3?
Zinc Zamak 3 conducts heat better: 113 W/m·K against 16.2 W/m·K for Stainless Steel 304.
Which expands less with temperature?
Stainless Steel 304 expands less: 16.9 µm/m·K against 27.4 µm/m·K for Zinc Zamak 3.