Solder Alloy 181 vs. Solder Alloy 721
Both solder alloy 181 and solder alloy 721 are otherwise unclassified metals. Both are furnished in the as-fabricated (no temper or treatment) condition.
For each property being compared, the top bar is solder alloy 181 and the bottom bar is solder alloy 721.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 18 | |
| 51 |
| Elongation at Break, % | 41 | |
| 17 |
| Poisson's Ratio | 0.44 | |
| 0.36 |
| Shear Modulus, GPa | 6.1 | |
| 19 |
| Tensile Strength: Ultimate (UTS), MPa | 27 | |
| 50 |
Thermal Properties
| Latent Heat of Fusion, J/g | 26 | |
| 61 |
| Melting Completion (Liquidus), °C | 310 | |
| 220 |
| Melting Onset (Solidus), °C | 300 | |
| 210 |
| Specific Heat Capacity, J/kg-K | 130 | |
| 220 |
| Thermal Conductivity, W/m-K | 24 | |
| 56 |
| Thermal Expansion, µm/m-K | 29 | |
| 22 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 9.3 | |
| 14 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 7.4 | |
| 17 |
Otherwise Unclassified Properties
| Density, g/cm3 | 11 | |
| 7.4 |
| Embodied Carbon, kg CO2/kg material | 6.2 | |
| 17 |
| Embodied Energy, MJ/kg | 100 | |
| 280 |
Common Calculations
| Stiffness to Weight: Axial, points | 0.86 | |
| 3.8 |
| Stiffness to Weight: Bending, points | 7.7 | |
| 17 |
| Strength to Weight: Axial, points | 0.66 | |
| 1.9 |
| Strength to Weight: Bending, points | 1.8 | |
| 4.1 |
| Thermal Diffusivity, mm2/s | 16 | |
| 34 |
| Thermal Shock Resistance, points | 3.8 | |
| 3.2 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0010 | |
| 0 to 0.0010 |
| Antimony (Sb), % | 0 to 0.2 | |
| 0 to 0.1 |
| Arsenic (As), % | 0 to 0.030 | |
| 0 to 0.030 |
| Bismuth (Bi), % | 0 to 0.1 | |
| 0.8 to 1.2 |
| Cadmium (Cd), % | 0 to 0.0020 | |
| 0 to 0.0020 |
| Copper (Cu), % | 0 to 0.080 | |
| 0.3 to 0.7 |
| 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), % | 96.2 to 98 | |
| 0 to 0.070 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 to 0.010 |
| Silver (Ag), % | 2.0 to 3.0 | |
| 2.3 to 2.7 |
| Tin (Sn), % | 0 to 0.25 | |
| 95 to 96.6 |
| Zinc (Zn), % | 0 to 0.0010 | |
| 0 to 0.0010 |