Solder Alloy 121 vs. Solder Alloy 123
Both solder alloy 121 and solder alloy 123 are otherwise unclassified metals. Both are furnished in the as-fabricated (no temper or treatment) condition. They have 90% of their average alloy composition in common.
For each property being compared, the top bar is solder alloy 121 and the bottom bar is solder alloy 123.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 11 | |
| 8.0 |
| Elastic (Young's, Tensile) Modulus, GPa | 21 | |
| 18 |
| Elongation at Break, % | 25 | |
| 45 |
| Poisson's Ratio | 0.43 | |
| 0.44 |
| Shear Modulus, GPa | 7.5 | |
| 6.2 |
| Tensile Strength: Ultimate (UTS), MPa | 32 | |
| 28 |
Thermal Properties
| Latent Heat of Fusion, J/g | 29 | |
| 26 |
| Melting Completion (Liquidus), °C | 290 | |
| 310 |
| Melting Onset (Solidus), °C | 230 | |
| 300 |
| Specific Heat Capacity, J/kg-K | 140 | |
| 130 |
| Thermal Conductivity, W/m-K | 31 | |
| 23 |
| Thermal Expansion, µm/m-K | 28 | |
| 29 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.8 | |
| 8.8 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 7.4 | |
| 7.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 75 |
| Density, g/cm3 | 11 | |
| 11 |
| Embodied Carbon, kg CO2/kg material | 5.6 | |
| 4.5 |
| Embodied Energy, MJ/kg | 93 | |
| 74 |
| Embodied Water, L/kg | 580 | |
| 500 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.1 | |
| 0.9 |
| Stiffness to Weight: Bending, points | 8.6 | |
| 7.8 |
| Strength to Weight: Axial, points | 0.84 | |
| 0.69 |
| Strength to Weight: Bending, points | 2.1 | |
| 1.8 |
| Thermal Diffusivity, mm2/s | 20 | |
| 16 |
| Thermal Shock Resistance, points | 3.9 | |
| 3.8 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0010 | |
| 0 to 0.0010 |
| Antimony (Sb), % | 0 to 0.5 | |
| 0 to 0.5 |
| Arsenic (As), % | 0 to 0.030 | |
| 0 to 0.030 |
| Bismuth (Bi), % | 0 to 0.25 | |
| 0 to 0.1 |
| Cadmium (Cd), % | 0 to 0.0050 | |
| 0 to 0.0050 |
| Copper (Cu), % | 0 to 0.080 | |
| 0 to 0.080 |
| Gold (Au), % | 0 to 0.050 | |
| 0 to 0.050 |
| Indium (In), % | 0 to 0.1 | |
| 0 to 0.1 |
| Iron (Fe), % | 0 to 0.020 | |
| 0 to 0.020 |
| Lead (Pb), % | 83.4 to 85.5 | |
| 93.5 to 95.5 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 to 0.010 |
| Silver (Ag), % | 0 to 0.1 | |
| 0 to 0.1 |
| Tin (Sn), % | 14.5 to 15.5 | |
| 4.5 to 5.5 |
| Zinc (Zn), % | 0 to 0.0010 | |
| 0 to 0.0010 |