Aluminum A380 vs. Stainless Steel 303

Compare Aluminum A380 vs. Stainless Steel 303 strength, stiffness, weight and thermal properties.

Change either side

Mechanical
Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD
Yield strength	160MPasourcetypical, 25 °C	275MPasourceOutokumpu typical (product P = hot rolled plate, transverse)
Ultimate tensile strength	320MPasourcetypical, 25 °C	585MPasourceOutokumpu typical
Elongation at break	3.5%sourcetypical	35%sourceOutokumpu typical, A5
Young's modulus (stiffness)	71GPasourcetypical, 25 °C	200GPasourceat RT (Table 12)
Density	2,713kg/m³sourcetypical at 68 °F	7,900kg/m³sourceat RT
Strength to weight	59kN·m/kg1.69x higher	34.8kN·m/kg
Stiffness to weight	26.2MN·m/kg3% higher	25.3MN·m/kg
Poisson's ratio	not sourced	0.3sourcedesign value (structural stainless steels)
Shear modulus	not sourced	76.9GPa
Bulk modulus	not sourced	167GPa
Speed of sound	5,116m/s	5,032m/s
Thermal
Thermal conductivity	96.2W/m·Ksourcetypical at 68 °F	15W/m·Ksourceat RT
Thermal expansion	21.8µm/m·Ksourcetypical, 68-572 °F (20-300 °C)	16µm/m·Ksourcemean, 20–100 °C
100 mm part over a 50 °C swing	109µm growth	80µm growth36% less
Specific heat	963J/kg·Ksourcetypical at 68 °F	500J/kg·Ksourceat RT
Heats up and cools (diffusivity)	36.8mm²/s9.7x faster	3.8mm²/s
Thermal shock resistance	not sourced	902W/m
Max service temperature	not sourced	871°Csourcecontinuous, scaling limit
Values for	A380 aluminium high-pressure die-casting alloy, typical properties; Rheocast Company (aluminium die caster, Germantown WI) A380 alloy data page.	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

Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Is Aluminum A380 stronger than Stainless Steel 303?

Stainless Steel 303 is stronger: its yield strength is 275 MPa against 160 MPa for Aluminum A380 (1.72x).

Which is lighter, Aluminum A380 or Stainless Steel 303?

Aluminum A380 is lighter: 2,713 kg/m³ against 7,900 kg/m³ for Stainless Steel 303.

Which is stiffer, Aluminum A380 or Stainless Steel 303?

Stainless Steel 303 is stiffer: Young's modulus 200 GPa against 71 GPa for Aluminum A380, so the same part in Stainless Steel 303 deflects less under the same load.

Which is lighter for the same job, Aluminum A380 or Stainless Steel 303?

For the same stiffness or strength: Aluminum A380 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum A380	Stainless Steel 303
Stiff rod or tie (tension)	lighter	3% heavier
Stiff beam (bending)	lighter	1.73x heavier
Stiff panel or plate	lighter	2.06x heavier
Strong rod or tie	lighter	1.69x heavier
Strong beam	lighter	2.03x heavier
Strong panel or plate	lighter	2.22x heavier

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 conducts heat better, Aluminum A380 or Stainless Steel 303?

Aluminum A380 conducts heat better: 96.2 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 21.8 µm/m·K for Aluminum A380.

Among 72 materials

Stiffness against density

Strength against density