Aluminum 1100-O vs. Aluminum 6061-T6

Compare Aluminum 1100-O vs. Aluminum 6061-T6 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 1100-O	Aluminum 6061-T6
Yield strength	35MPa1	276MPa27.89x stronger
Ultimate tensile strength	90MPa1	310MPa23.44x stronger
Elongation at break	35%12.06x more ductile	17%2
Young's modulus (stiffness)	69GPa1	68.3GPa2
Density	2,710kg/m³1	2,700kg/m³2
Strength to weight	12.9kN·m/kg	102kN·m/kg7.91x higher
Stiffness to weight	25.5MN·m/kg	25.3MN·m/kg
Poisson's ratio	not sourced	0.333
Shear modulus	not sourced	25.7GPa
Bulk modulus	not sourced	67GPa
Speed of sound	5,046m/s	5,030m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 1100-O	Aluminum 6061-T6
Thermal conductivity	222W/m·K133% more heat through a fin	167W/m·K2
Thermal expansion	23.6µm/m·K1	23.6µm/m·K2
100 mm part over a 50 °C swing	118µm growth	118µm growth
Specific heat	base material901J/kg·K4	896J/kg·K2
Heats up and cools (diffusivity)	90.9mm²/s32% faster	69mm²/s
Thermal shock resistance	not sourced	19,159W/m
Melting point	melting range640–655°C1	solidus-liquidus582–652°C2

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, Hydro

Aluminum 1100-O: 1100-O (annealed) commercially pure aluminium, Kaiser Aluminum Tube & Pipe Alloy 1100 Technical Data (Rev. 05/06), typical properties; specific heat from Hydro EN AW-1050A (99.5% Al) extruded-products datasheet (10/2018).
Aluminum 6061-T6: 6061-T6/T651, Kaiser Aluminum typical properties; Poisson from MIL-HDBK-5J

1
Alloy 1100 Tube & Pipe Technical Data, Rev. 05/06Kaiser Aluminumarchived copyAluminum 1100-O · Yield strength: typical, O, 0.0625 in specimenAluminum 1100-O · Ultimate tensile strength: typical, OAluminum 1100-O · Elongation at break: typical, O, in 4DAluminum 1100-O · Young's modulus (stiffness): typicalAluminum 1100-O · Density: nominal, 20 °CAluminum 1100-O · Thermal conductivity: typical, O, 20 °CAluminum 1100-O · Thermal expansion: typical, mean 20-100 °CAluminum 1100-O · Melting point: melting range
2
Alloy 6061 Sheet, Coil & Plate Technical DataKaiser Aluminumarchived copyAluminum 6061-T6 · Yield strength: typical, 0.2% offset, .500 in dia specimenAluminum 6061-T6 · Ultimate tensile strength: typicalAluminum 6061-T6 · Elongation at break: typical, in 4D, 0.500 in dia specimenAluminum 6061-T6 · Young's modulus (stiffness): typicalAluminum 6061-T6 · Density: nominalAluminum 6061-T6 · Thermal conductivity: typical, 20 °CAluminum 6061-T6 · Thermal expansion: typical, mean 20-100 °CAluminum 6061-T6 · Specific heat: typical, at 100 °CAluminum 6061-T6 · Melting point: solidus-liquidus
3
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseAluminum 6061-T6 · Poisson's ratio: typical (handbook physical constant)
4
Technical Datasheet, Extruded Products: Alloy EN AW-1050AHydroAluminum 1100-O · Specific heat: base material: commercially pure aluminium EN AW-1050A (Hydro), 20 °C

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 1100-O stronger than Aluminum 6061-T6?

Aluminum 6061-T6 is stronger: its yield strength is 276 MPa against 35 MPa for Aluminum 1100-O (7.89x).

Which is lighter, Aluminum 1100-O or Aluminum 6061-T6?

Aluminum 6061-T6 is lighter: 2,700 kg/m³ against 2,710 kg/m³ for Aluminum 1100-O.

Which is stiffer, Aluminum 1100-O or Aluminum 6061-T6?

Aluminum 1100-O is stiffer: Young's modulus 69 GPa against 68.3 GPa for Aluminum 6061-T6, so the same part in Aluminum 1100-O deflects less under the same load.

Which is lighter for the same job, Aluminum 1100-O or Aluminum 6061-T6?

For the same stiffness or strength: Aluminum 6061-T6 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 1100-O	Aluminum 6061-T6
Stiff rod or tie (tension)	about equal	about equal
Stiff beam (bending)	about equal	about equal
Stiff panel or plate	about equal	about equal
Strong rod or tie	7.91x heavier	lighter
Strong beam	3.98x heavier	lighter
Strong panel or plate	2.82x 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 1100-O or Aluminum 6061-T6?

Aluminum 1100-O stretches further before it breaks: 35% elongation at break against 17% for Aluminum 6061-T6.

Thermal

Which conducts heat better, Aluminum 1100-O or Aluminum 6061-T6?

Aluminum 1100-O conducts heat better: 222 W/m·K against 167 W/m·K for Aluminum 6061-T6.

Which expands less with temperature?

Aluminum 1100-O expands less: 23.6 µm/m·K against 23.6 µm/m·K for Aluminum 6061-T6.