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ISO Solder Alloy 113 (Pb55Sn45)

Solder alloy 113 is a lead-based soldering alloy. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. 113 is the ISO numeric designation for this material. Older literature may refer to this material as S-Pb55Sn45, but this is now discouraged.

It has a moderately high heat capacity among lead-based solder alloys. In addition, it has a fairly high thermal conductivity and a moderately high electrical conductivity.

The graph bars on the material properties cards below compare solder alloy 113 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

Elastic (Young's, Tensile) Modulus

32 GPa 4.6 x 106 psi

Elongation at Break

32 %

Poisson's Ratio


Shear Modulus

11 GPa 1.6 x 106 psi

Tensile Strength: Ultimate (UTS)

39 MPa 5.7 x 103 psi

Thermal Properties

Latent Heat of Fusion

40 J/g

Melting Completion (Liquidus)

230 °C 440 °F

Melting Onset (Solidus)

180 °C 360 °F

Specific Heat Capacity

170 J/kg-K 0.041 BTU/lb-°F

Thermal Conductivity

46 W/m-K 27 BTU/h-ft-°F

Thermal Expansion

26 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

10 % IACS

Electrical Conductivity: Equal Weight (Specific)

9.8 % IACS

Otherwise Unclassified Properties


9.5 g/cm3 590 lb/ft3

Embodied Carbon

8.9 kg CO2/kg material

Embodied Energy

150 MJ/kg 65 x 103 BTU/lb

Embodied Water

800 L/kg 95 gal/lb

Common Calculations

Stiffness to Weight: Axial

1.8 points

Stiffness to Weight: Bending

11 points

Strength to Weight: Axial

1.1 points

Strength to Weight: Bending

2.7 points

Thermal Diffusivity

28 mm2/s

Thermal Shock Resistance

3.4 points

Alloy Composition

Lead (Pb)Pb 53.4 to 55.5
Tin (Sn)Sn 44.5 to 45.5
Antimony (Sb)Sb 0 to 0.5
Bismuth (Bi)Bi 0 to 0.25
Silver (Ag)Ag 0 to 0.1
Indium (In)In 0 to 0.1
Copper (Cu)Cu 0 to 0.080
Gold (Au)Au 0 to 0.050
Arsenic (As)As 0 to 0.030
Iron (Fe)Fe 0 to 0.020
Nickel (Ni)Ni 0 to 0.010
Cadmium (Cd)Cd 0 to 0.0050
Aluminum (Al)Al 0 to 0.0010
Zinc (Zn)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