ISO Solder Alloy 122 (Pb90Sn10)
Solder alloy 122 is a lead-based soldering alloy. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. 122 is the ISO numeric designation for this material. Older literature may refer to this material as S-Pb90Sn10, but this is now discouraged.
It has a fairly low embodied energy among lead-based solder alloys. In addition, it has a moderately low electrical conductivity and a moderately low thermal conductivity.
The graph bars on the material properties cards below compare solder alloy 122 to: lead-based solder alloys (top), all alloys in the same category (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
10
Elastic (Young's, Tensile) Modulus
20 GPa 2.8 x 106 psi
Elongation at Break
30 %
Poisson's Ratio
0.43
Shear Modulus
6.9 GPa 1.0 x 106 psi
Tensile Strength: Ultimate (UTS)
30 MPa 4.4 x 103 psi
Thermal Properties
Latent Heat of Fusion
27 J/g
Melting Completion (Liquidus)
300 °C 580 °F
Melting Onset (Solidus)
270 °C 510 °F
Specific Heat Capacity
140 J/kg-K 0.033 BTU/lb-°F
Thermal Conductivity
25 W/m-K 14 BTU/h-ft-°F
Thermal Expansion
28 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
8.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
7.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
75 % relative
Density
11 g/cm3 680 lb/ft3
Embodied Carbon
5.0 kg CO2/kg material
Embodied Energy
84 MJ/kg 36 x 103 BTU/lb
Embodied Water
540 L/kg 64 gal/lb
Common Calculations
Stiffness to Weight: Axial
1.0 points
Stiffness to Weight: Bending
8.2 points
Strength to Weight: Axial
0.77 points
Strength to Weight: Bending
2.0 points
Thermal Diffusivity
17 mm2/s
Thermal Shock Resistance
3.9 points
Alloy Composition
| Pb | 88.4 to 90.5 | |
| Sn | 9.5 to 10.5 | |
| Sb | 0 to 0.5 | |
| Bi | 0 to 0.25 | |
| Ag | 0 to 0.1 | |
| In | 0 to 0.1 | |
| Cu | 0 to 0.080 | |
| Au | 0 to 0.050 | |
| As | 0 to 0.030 | |
| Fe | 0 to 0.020 | |
| Ni | 0 to 0.010 | |
| Cd | 0 to 0.0050 | |
| Al | 0 to 0.0010 | |
| Zn | 0 to 0.0010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ISO 9453: Soft solder alloys - Chemical compositions and forms