Copper C12200 vs. Solder SAC305

Compare Copper C12200 vs. Solder SAC305 strength, stiffness, weight and thermal properties.

Mechanical	Copper C12200	Solder SAC305
Yield strength	69MPa13.14x stronger	22MPa2
Ultimate tensile strength	221MPa15.58x stronger	39.6MPa2
Elongation at break	45%1	49%2
Young's modulus (stiffness)	117GPa117x stiffer	6.9GPa2
Density	8,941kg/m³1	7,350kg/m³222% lighter
Strength to weight	7.72kN·m/kg2.58x higher	2.99kN·m/kg
Stiffness to weight	13.1MN·m/kg14x higher	0.939MN·m/kg
Poisson's ratio	0.343	0.352
Shear modulus	43.7GPa17.1x stiffer in shear	2.56GPa
Bulk modulus	122GPa15.9x higher	7.67GPa
Speed of sound	3,621m/s3.74x faster	969m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Copper C12200	Solder SAC305
Thermal conductivity	339W/m·K15.56x more heat through a fin	61W/m·K2
Thermal expansion	16.9µm/m·K130% less	mean21.9µm/m·K4
100 mm part over a 50 °C swing	84.5µm growth30% less	110µm growth
Specific heat	385J/kg·K11.66x higher	232J/kg·K4
Heats up and cools (diffusivity)	98.5mm²/s2.75x faster	35.8mm²/s
Thermal shock resistance	7,799W/m35% more resistant	5,773W/m
Melting point	liquidus1,083°C1	solidus-liquidus217–220°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: Copper Development Association, Indium Corporation, Wieland, MacDermid Alpha

Copper C12200: C12200 phosphorus-deoxidized copper (DHP, the air-conditioning and refrigeration tube copper), tube annealed to 0.050 mm grain size (OS050), 0.065 in. wall, copper.org typical values
Solder SAC305: 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
C12200 Alloy (copper.org)Copper Development Associationarchived copyCopper C12200 · Yield strength: typical, 0.5% extension under load, 0.065 in. tubeCopper C12200 · Ultimate tensile strength: typical, 0.065 in. tubeCopper C12200 · Elongation at break: typical, 0.065 in. tubeCopper C12200 · Young's modulus (stiffness): typicalCopper C12200 · Density: nominalCopper C12200 · Thermal conductivity: typical, 20 °CCopper C12200 · Thermal expansion: typical, mean 20-100 °CCopper C12200 · Specific heat: typical, 20 °CCopper C12200 · Melting point: liquidus
2
Indalloy 256 (SAC305) for Preforms Product Data Sheet (100346 R0)Indium Corporationarchived copySolder SAC305 · Yield strength: typicalSolder SAC305 · Ultimate tensile strength: typicalSolder SAC305 · Elongation at break: typicalSolder SAC305 · Young's modulus (stiffness): typical, temperature and strain rate not statedSolder SAC305 · Density: typicalSolder SAC305 · Poisson's ratio: typicalSolder SAC305 · Thermal conductivity: typical, temperature not statedSolder SAC305 · Melting point: solidus-liquidus
3
Wieland-K19 (Cu-DHP, C12200) Data SheetWielandarchived copyCopper C12200 · Poisson's ratio: reference value at room temperature (Wieland-K19 = Cu-DHP = C12200, rolled products)
4
ALPHA Vaculoy SAC Alloys Technical Data Sheet (2023)MacDermid AlphaSolder SAC305 · Thermal expansion: mean, 20-100 °C (MacDermid Alpha)Solder SAC305 · Specific heat: typical (MacDermid Alpha)

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 Copper C12200 stronger than Solder SAC305?

Copper C12200 is stronger: its yield strength is 69 MPa against 22 MPa for Solder SAC305 (3.14x).

Which is lighter, Copper C12200 or Solder SAC305?

Solder SAC305 is lighter: 7,350 kg/m³ against 8,941 kg/m³ for Copper C12200.

Which is stiffer, Copper C12200 or Solder SAC305?

Copper C12200 is stiffer: Young's modulus 117 GPa against 6.9 GPa for Solder SAC305, so the same part in Copper C12200 deflects less under the same load.

Which is lighter for the same job, Copper C12200 or Solder SAC305?

For the same stiffness or strength: Copper C12200 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	Copper C12200	Solder SAC305
Stiff rod or tie (tension)	lighter	14x heavier
Stiff beam (bending)	lighter	3.39x heavier
Stiff panel or plate	lighter	2.11x heavier
Strong rod or tie	lighter	2.58x heavier
Strong beam	lighter	1.76x heavier
Strong panel or plate	lighter	46% 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).

Thermal

Which conducts heat better, Copper C12200 or Solder SAC305?

Copper C12200 conducts heat better: 339 W/m·K against 61 W/m·K for Solder SAC305.

Which expands less with temperature?

Copper C12200 expands less: 16.9 µm/m·K against 21.9 µm/m·K for Solder SAC305.