Aluminum 3003-O vs. Aluminum 7075-T6

Compare Aluminum 3003-O vs. Aluminum 7075-T6 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 3003-O	Aluminum 7075-T6
Yield strength	40MPa1	503MPa212.6x stronger
Ultimate tensile strength	110MPa1	572MPa25.2x stronger
Elongation at break	30%12.73x more ductile	11%2
Young's modulus (stiffness)	69GPa1	71GPa2
Density	2,730kg/m³1	2,800kg/m³3
Strength to weight	14.7kN·m/kg	180kN·m/kg12.3x higher
Stiffness to weight	25.3MN·m/kg	25.4MN·m/kg
Poisson's ratio	not sourced	0.334
Shear modulus	not sourced	26.7GPa
Bulk modulus	not sourced	69.6GPa
Speed of sound	5,027m/s	5,036m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 3003-O	Aluminum 7075-T6
Thermal conductivity	193W/m·K148% more heat through a fin	130W/m·K3
Thermal expansion	23.2µm/m·K1	23.4µm/m·K3
100 mm part over a 50 °C swing	116µm growth	117µm growth
Specific heat	not sourced	960J/kg·K3
Heats up and cools (diffusivity)	not sourced	48.4mm²/s
Thermal shock resistance	not sourced	26,370W/m
Melting point	melting range640–655°C1	melting range532–635°C3

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources4 documents: Kaiser Aluminum, U.S. Department of Defense

Aluminum 3003-O: 3003-O (annealed) aluminium-manganese alloy, the heat-exchanger tube and brazing alloy, Kaiser Aluminum Tube & Pipe Alloy 3003 Technical Data (Rev. 05/06), typical properties; specific heat from the NIST cryogenic 3003-F fit at 293 K.
Aluminum 7075-T6: 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J

1
Alloy 3003 Tube & Pipe Technical Data, Rev. 05/06Kaiser Aluminumarchived copyAluminum 3003-O · Yield strength: typical, O, 0.0625 in specimenAluminum 3003-O · Ultimate tensile strength: typical, OAluminum 3003-O · Elongation at break: typical, O, in 4DAluminum 3003-O · Young's modulus (stiffness): typicalAluminum 3003-O · Density: nominal, 20 °CAluminum 3003-O · Thermal conductivity: typical, O, 20 °CAluminum 3003-O · Thermal expansion: typical, mean 20-100 °CAluminum 3003-O · Melting point: melting range
2
Alloy 7075 Rod & Bar Technical DataKaiser Aluminumarchived copyAluminum 7075-T6 · Yield strength: typical, 0.2% offset, .500 in dia specimenAluminum 7075-T6 · Ultimate tensile strength: typicalAluminum 7075-T6 · Elongation at break: typical, in 4DAluminum 7075-T6 · Young's modulus (stiffness): typical
3
Alloy 7075 Sheet, Coil & Plate Technical DataKaiser Aluminumarchived copyAluminum 7075-T6 · Density: nominalAluminum 7075-T6 · Thermal conductivity: typical, 20 °C, T651Aluminum 7075-T6 · Thermal expansion: typical, mean 20-100 °CAluminum 7075-T6 · Specific heat: typical, at 100 °CAluminum 7075-T6 · Melting point: melting range
4
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseAluminum 7075-T6 · Poisson's ratio: typical (handbook physical constant)

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 Aluminum 3003-O stronger than Aluminum 7075-T6?

Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 40 MPa for Aluminum 3003-O (12.6x).

Which is lighter, Aluminum 3003-O or Aluminum 7075-T6?

Aluminum 3003-O is lighter: 2,730 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.

Which is stiffer, Aluminum 3003-O or Aluminum 7075-T6?

Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 69 GPa for Aluminum 3003-O, so the same part in Aluminum 7075-T6 deflects less under the same load.

Which is lighter for the same job, Aluminum 3003-O or Aluminum 7075-T6?

For the same stiffness or strength: Aluminum 3003-O is lighter for a stiff beam (bending), stiff panel or plate; Aluminum 7075-T6 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 3003-O	Aluminum 7075-T6
Stiff rod or tie (tension)	about equal	about equal
Stiff beam (bending)	lighter	1% heavier
Stiff panel or plate	lighter	2% heavier
Strong rod or tie	12.3x heavier	lighter
Strong beam	5.27x heavier	lighter
Strong panel or plate	3.46x 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, Aluminum 3003-O or Aluminum 7075-T6?

Aluminum 3003-O stretches further before it breaks: 30% elongation at break against 11% for Aluminum 7075-T6.

Thermal

Which conducts heat better, Aluminum 3003-O or Aluminum 7075-T6?

Aluminum 3003-O conducts heat better: 193 W/m·K against 130 W/m·K for Aluminum 7075-T6.

Which expands less with temperature?

Aluminum 3003-O expands less: 23.2 µm/m·K against 23.4 µm/m·K for Aluminum 7075-T6.