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Solder & Low-Melting Alloy Bi58Sn42 vs Wood's Metal

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Bi58Sn42 and Wood's Metal are both solder & low-melting alloy grades. Bi58Sn42 is the stronger of the two: yield strength 42 MPa (6.09 ksi) against 25 MPa (3.63 ksi) for Wood's Metal, about 68% more; tensile strength follows at 65 MPa (9.43 ksi) vs 42 MPa (6.09 ksi). Bi58Sn42 is the more ductile: elongation 40% versus 25% for Wood's Metal, and Bi58Sn42 is harder (22 HB vs 11 HB). Bi58Sn42 is lighter (8.56 g/cm³ vs 9.7 g/cm³ for Wood's Metal) and Bi58Sn42 is stiffer (42 GPa vs 9.7 GPa).

Bi58Sn42Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Bi58Sn42 vs Wood's Metal: properties

Bi58Sn42Wood's Metal

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

42 GPa6.1 Msi
9.7 GPa1.4 Msi

Shear Modulus

16 GPa2.3 Msi
3.6 GPa0.52 Msi

Bulk Modulus

41 GPa5.9 Msi
—

Poisson's Ratio

0.33
0.35

Tensile Strength (Ultimate)

65 MPa9.4 ksi
42 MPa6.1 ksi

Yield Strength (0.2% offset)

42 MPa6.1 ksi
25 MPa3.6 ksi

Elongation at Break

40%
25%

Shear Strength

45 MPa6.5 ksi
28 MPa4.1 ksi

Fatigue Strength (Endurance Limit)

20 MPa2.9 ksi
12 MPa1.7 ksi

Hardness, Brinell

22 HB
11 HB

Hardness, Vickers

23 HV
12 HV

Reduction in Area

—
30%

Compressive Strength

—
60 MPa8.7 ksi

Charpy V-Notch Impact (RT)

—
2 J1.5 ft·lbf

Physical

Density and transition temperatures.

Density

8.56 g/cm³0.31 lb/in³
9.7 g/cm³0.35 lb/in³

Melting Point (Solidus)

138°C280 °F
70°C158 °F

Liquidus Temperature

138°C280 °F
72°C162 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

19 W/m·K11 BTU/hr·ft·°F
13 W/m·K7.5 BTU/hr·ft·°F

Specific Heat Capacity

167 J/kg·K0.04 BTU/lb·°F
168 J/kg·K0.04 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
23 µm/m·K12.8 µin/in·°F

Latent Heat of Fusion

45 J/g19.3 BTU/lb
35 J/g15 BTU/lb

Max Service Temperature (continuous)

80°C176 °F
40°C104 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5 % IACS
3 % IACS

Electrical Resistivity

3.4×10⁻⁷ Ω·m13.4 µΩ·in
5.8×10⁻⁷ Ω·m22.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

50 / 100
38 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.45 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

30 / 100
35 / 100

Weldability

20 / 100
15 / 100

Formability (cold)

60 / 100
40 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

95 / 100
85 / 100

Machinability Rating (AISI 1212 = 100 %)

—
30%

Same in both: Polishability 30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

190 MJ/kg81,685 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

500 L/kg59.9 gal/lb
—

Typical Recycled Content

25%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

8 kN·m/kg
4 kN·m/kg

Specific Stiffness (E / density)

4.9 MN·m/kg
1 MN·m/kg

Modulus of Resilience

21 kJ/m³
32 kJ/m³

Thermal Diffusivity

13.3 mm²/s
8 mm²/s

Same in both: Thermal Shock Resistance Index 2

Strength versus weight

Yield strength against density for every solder & low-melting alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

125102050891011Density (g/cm³)Yield strength (MPa) — log scaleBi58Sn42Wood's Metal

Manufacturing and finishing

CapabilityBi58Sn42Wood's Metal
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Bi58Sn42 vs Wood's Metal — frequently asked

Is Bi58Sn42 stronger than Wood's Metal?

Yes. Bi58Sn42 has a typical yield strength of 42 MPa (6.09 ksi) against 25 MPa (3.63 ksi) for Wood's Metal — about 68% more. Tensile strength is 65 MPa (9.43 ksi) vs 42 MPa (6.09 ksi).

Which is cheaper, Bi58Sn42 or Wood's Metal?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, Bi58Sn42 or Wood's Metal?

Wood's Metal. Its machinability rates fair (35/100) against poor (30/100) for Bi58Sn42; for welding the order is Bi58Sn42 first (poor, 20/100) then Wood's Metal (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Bi58Sn42 and Wood's Metal side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.