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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Sources5 documents: Outokumpu, Nathan Trotter, Steel Construction Institute, Eastern Alloys, Carpenter Technology
Stainless Steel 303
1.4305 / UNS S30300, Outokumpu typical values (hot rolled, solution annealed) from 'Steel Grades, Properties and Global Standards'; max service from Carpenter CarTech 303 datasheet
Zinc Zamak 3
Zamak 3 (ASTM B86 die cast), Nathan Trotter (zinc alloy producer) technical data sheet, typical values
1
Steel Grades, Properties and Global StandardsOutokumpuarchived copyStainless Steel 303 · Yield strength: Outokumpu typical (product P = hot rolled plate, transverse)Stainless Steel 303 · Ultimate tensile strength: Outokumpu typicalStainless Steel 303 · Elongation at break: Outokumpu typical, A5Stainless Steel 303 · Young's modulus (stiffness): at RT (Table 12)Stainless Steel 303 · Density: at RTStainless Steel 303 · Thermal conductivity: at RTStainless Steel 303 · Thermal expansion: mean, 20–100 °CStainless Steel 303 · Specific heat: at RT
Design Manual for Structural Stainless Steel, 4th Edition (P413)Steel Construction Institutearchived copyStainless Steel 303 · 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
5
Carpenter Stainless Type 303 Data SheetCarpenter Technologyarchived copyStainless Steel 303 · Max service temperature: continuous, scaling limit
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 303 stronger than Zinc Zamak 3?
Stainless Steel 303 is stronger: its yield strength is 275 MPa against 221 MPa for Zinc Zamak 3 (24%).
Which is lighter, Stainless Steel 303 or Zinc Zamak 3?
Zinc Zamak 3 is lighter: 6,600 kg/m³ against 7,900 kg/m³ for Stainless Steel 303.
Which is stiffer, Stainless Steel 303 or Zinc Zamak 3?
Stainless Steel 303 is stiffer: Young's modulus 200 GPa against 85.5 GPa for Zinc Zamak 3, so the same part in Stainless Steel 303 deflects less under the same load.
Which is lighter for the same job, Stainless Steel 303 or Zinc Zamak 3?
For the same stiffness or strength: Stainless Steel 303 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie; Zinc Zamak 3 is lighter for a strong beam, strong panel or plate.
Part that must be
Stainless Steel 303
Zinc Zamak 3
Stiff rod or tie (tension)
lighter
1.95x heavier
Stiff beam (bending)
lighter
28% heavier
Stiff panel or plate
lighter
11% heavier
Strong rod or tie
lighter
4% heavier
Strong beam
3% heavier
lighter
Strong panel or plate
7% 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 303 or Zinc Zamak 3?
Stainless Steel 303 stretches further before it breaks: 35% elongation at break against 10% for Zinc Zamak 3.
Thermal
Which conducts heat better, Stainless Steel 303 or Zinc Zamak 3?
Zinc Zamak 3 conducts heat better: 113 W/m·K against 15 W/m·K for Stainless Steel 303.
Which expands less with temperature?
Stainless Steel 303 expands less: 16 µm/m·K against 27.4 µm/m·K for Zinc Zamak 3.