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).
ATI 316 (UNS S31600), annealed 1.0 mm sheet, ATI technical data sheet (2012); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual
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 1100-O stronger than Stainless Steel 316?
Stainless Steel 316 is stronger: its yield strength is 265 MPa against 35 MPa for Aluminum 1100-O (7.57x).
Which is lighter, Aluminum 1100-O or Stainless Steel 316?
Aluminum 1100-O is lighter: 2,710 kg/m³ against 8,027 kg/m³ for Stainless Steel 316.
Which is stiffer, Aluminum 1100-O or Stainless Steel 316?
Stainless Steel 316 is stiffer: Young's modulus 200 GPa against 69 GPa for Aluminum 1100-O, so the same part in Stainless Steel 316 deflects less under the same load.
Which is lighter for the same job, Aluminum 1100-O or Stainless Steel 316?
For the same stiffness or strength: Aluminum 1100-O is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong panel or plate; Stainless Steel 316 is lighter for a strong rod or tie, strong beam.
Part that must be
Aluminum 1100-O
Stainless Steel 316
Stiff rod or tie (tension)
lighter
2% heavier
Stiff beam (bending)
lighter
1.74x heavier
Stiff panel or plate
lighter
2.08x heavier
Strong rod or tie
2.56x heavier
lighter
Strong beam
30% heavier
lighter
Strong panel or plate
lighter
8% 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 1100-O or Stainless Steel 316?
Aluminum 1100-O conducts heat better: 222 W/m·K against 14.6 W/m·K for Stainless Steel 316.
Which expands less with temperature?
Stainless Steel 316 expands less: 16.5 µm/m·K against 23.6 µm/m·K for Aluminum 1100-O.