SAC305 (Sn96.5Ag3.0Cu0.5) solder alloy, bulk; Indium Corporation Indalloy 256 (SAC305) for Preforms product data sheet (Form No. 100346 R0, 2024), selected properties, test temperature not stated; expansion and specific heat from MacDermid Alpha VACULOY SAC TDS (06 September 2023).
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 Solder SAC305 stronger than Stainless Steel 303?
Stainless Steel 303 is stronger: its yield strength is 275 MPa against 22 MPa for Solder SAC305 (12.5x).
Which is lighter, Solder SAC305 or Stainless Steel 303?
Solder SAC305 is lighter: 7,350 kg/m³ against 7,900 kg/m³ for Stainless Steel 303.
Which is stiffer, Solder SAC305 or Stainless Steel 303?
Stainless Steel 303 is stiffer: Young's modulus 200 GPa against 6.9 GPa for Solder SAC305, so the same part in Stainless Steel 303 deflects less under the same load.
Which is lighter for the same job, Solder SAC305 or Stainless Steel 303?
For the same stiffness or strength: Stainless Steel 303 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
Solder SAC305
Stainless Steel 303
Stiff rod or tie (tension)
27x heavier
lighter
Stiff beam (bending)
5.01x heavier
lighter
Stiff panel or plate
2.86x heavier
lighter
Strong rod or tie
11.6x heavier
lighter
Strong beam
5.01x heavier
lighter
Strong panel or plate
3.29x 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 conducts heat better, Solder SAC305 or Stainless Steel 303?
Solder SAC305 conducts heat better: 61 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 21.9 µm/m·K for Solder SAC305.