Aluminum 3003-O vs. Steel A992

Compare Aluminum 3003-O vs. Steel A992 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 3003-O	Steel A992
Yield strength	40MPa1	385MPa29.63x stronger
Ultimate tensile strength	110MPa1	505MPa24.59x stronger
Elongation at break	30%124% more ductile	24.2%2
Young's modulus (stiffness)	69GPa1	design value200GPa3
Density	2,730kg/m³12.88x lighter	7,850kg/m³4
Strength to weight	14.7kN·m/kg	49kN·m/kg3.35x higher
Stiffness to weight	25.3MN·m/kg	25.5MN·m/kg
Poisson's ratio	not sourced	design value0.33
Shear modulus	not sourced	76.9GPa
Bulk modulus	not sourced	167GPa
Speed of sound	5,027m/s	5,048m/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	Steel A992
Thermal conductivity	193W/m·K14.02x more heat through a fin	48W/m·K4
Thermal expansion	23.2µm/m·K1	12µm/m·K41.93x less
100 mm part over a 50 °C swing	116µm growth	60µm growth1.93x less
Specific heat	not sourced	base material460–480J/kg·K5
Heats up and cools (diffusivity)	not sourced	13mm²/s
Thermal shock resistance	not sourced	5,390W/m
Melting point	melting range640–655°C1	not sourced

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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Sources5 documents: Kaiser Aluminum, American Institute of Steel Construction, bauforumstahl (ArcelorMittal), Ovako

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.
Steel A992: ASTM A992 W-shapes; Fy/Fu specified minimums from AISC publications (AISC 360-16 Commentary; Modern Steel Construction); elastic constants AISC 360; physical constants from the bauforumstahl structural-steel EPD, which names A992 among covered product standards.

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
Updating Standard Shape Material Properties Database for Design and ReliabilityAmerican Institute of Steel Constructionarchived copySteel A992 · Yield strength: typical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey), as reported by AISCSteel A992 · Ultimate tensile strength: typical: mean of 20,295 A992 flange mill-test coupons (1998 SSPC survey)Steel A992 · Elongation at break: typical: mean of 24,847 A992 mill-test elongations, web and flange (1998 SSPC mill data), as reported by AISC
3
ANSI/AISC 360-16 Specification for Structural Steel Buildings, with CommentaryAmerican Institute of Steel Constructionarchived copySteel A992 · Young's modulus (stiffness): design value (AISC 360-16)Steel A992 · Poisson's ratio: design value (AISC 360-16 Commentary)
4
Environmental Product Declaration: Structural Steel Sections and Merchant Bars (2023)bauforumstahl (ArcelorMittal)archived copySteel A992 · Density: nominal (constructional data)Steel A992 · Thermal conductivity: nominal at 20 °CSteel A992 · Thermal expansion: nominal (constructional data, no temperature range stated)
5
S275JR Steel GradeOvakoSteel A992 · Specific heat: base material: EN S275JR unalloyed structural steel (the EN counterpart of A36), typical, 50/100 °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 3003-O stronger than Steel A992?

Steel A992 is stronger: its yield strength is 385 MPa against 40 MPa for Aluminum 3003-O (9.63x).

Which is lighter, Aluminum 3003-O or Steel A992?

Aluminum 3003-O is lighter: 2,730 kg/m³ against 7,850 kg/m³ for Steel A992.

Which is stiffer, Aluminum 3003-O or Steel A992?

Steel A992 is stiffer: Young's modulus 200 GPa against 69 GPa for Aluminum 3003-O, so the same part in Steel A992 deflects less under the same load.

Which is lighter for the same job, Aluminum 3003-O or Steel A992?

For the same stiffness or strength: Aluminum 3003-O is lighter for a stiff beam (bending), stiff panel or plate; Steel A992 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 3003-O	Steel A992
Stiff rod or tie (tension)	about equal	about equal
Stiff beam (bending)	lighter	1.69x heavier
Stiff panel or plate	lighter	2.02x heavier
Strong rod or tie	3.35x heavier	lighter
Strong beam	1.57x heavier	lighter
Strong panel or plate	8% 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 Steel A992?

Aluminum 3003-O stretches further before it breaks: 30% elongation at break against 24.2% for Steel A992.

Thermal

Which conducts heat better, Aluminum 3003-O or Steel A992?

Aluminum 3003-O conducts heat better: 193 W/m·K against 48 W/m·K for Steel A992.

Which expands less with temperature?

Steel A992 expands less: 12 µm/m·K against 23.2 µm/m·K for Aluminum 3003-O.