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

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Bi58Sn42 and Field's Metal are both solder & low-melting alloy grades. Bi58Sn42 is the stronger of the two: yield strength 42 MPa (6.09 ksi) against 6 MPa (0.87 ksi) for Field's Metal, about 7.0 times as much; tensile strength follows at 65 MPa (9.43 ksi) vs 11 MPa (1.6 ksi). Bi58Sn42 is harder — 22 HB against 7 HB for Field's Metal — which matters for wear surfaces and threads. Field's Metal is lighter (7.88 g/cm³ vs 8.56 g/cm³ for Bi58Sn42) and Bi58Sn42 is stiffer (42 GPa vs 10 GPa). On the shop floor, Field's Metal forms better (excellent vs good).

Bi58Sn42Choose it when strength drives the design, or when surface hardness matters.

Field's MetalChoose it when weight is the constraint.

Bi58Sn42 vs Field's Metal: properties

Bi58Sn42Field's Metal

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

42 GPa6.1 Msi
10 GPa1.5 Msi

Shear Modulus

16 GPa2.3 Msi
—

Bulk Modulus

41 GPa5.9 Msi
—

Poisson's Ratio

0.33
0.35

Tensile Strength (Ultimate)

65 MPa9.4 ksi
11 MPa1.6 ksi

Yield Strength (0.2% offset)

42 MPa6.1 ksi
6 MPa0.87 ksi

Shear Strength

45 MPa6.5 ksi
8 MPa1.2 ksi

Fatigue Strength (Endurance Limit)

20 MPa2.9 ksi
—

Hardness, Brinell

22 HB
7 HB

Hardness, Vickers

23 HV
—

Compressive Strength

—
25 MPa3.6 ksi

Same in both: Elongation at Break 40%

Physical

Density and transition temperatures.

Density

8.56 g/cm³0.31 lb/in³
7.88 g/cm³0.28 lb/in³

Melting Point (Solidus)

138°C280 °F
62°C144 °F

Liquidus Temperature

138°C280 °F
62°C144 °F

Thermal

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

Specific Heat Capacity

167 J/kg·K0.04 BTU/lb·°F
200 J/kg·K0.05 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
29 J/g12.5 BTU/lb

Max Service Temperature (continuous)

80°C176 °F
40°C104 °F

Min Service Temperature

-40°C-40 °F
-60°C-76 °F

Same in both: Thermal Conductivity 19 W/m·K11 BTU/hr·ft·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

5 % IACS
3.3 % IACS

Electrical Resistivity

3.4×10⁻⁷ Ω·m13.4 µΩ·in
5.3×10⁻⁷ Ω·m20.9 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.45 V
—

Corrosion Resistance

50 / 100
55 / 100

Manufacturability

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

Formability (cold)

60 / 100
85 / 100

Castability

90 / 100
95 / 100

Polishability

30 / 100
40 / 100

Same in both: Machinability 30 / 100 · Weldability 20 / 100 · Brazeability / Solderability 95 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

190 MJ/kg81,685 BTU/lb
1,100 MJ/kg472,915 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
72 kg CO₂/kg

Embodied Water

500 L/kg59.9 gal/lb
—

Typical Recycled Content

25%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

8 kN·m/kg
1 kN·m/kg

Specific Stiffness (E / density)

4.9 MN·m/kg
1.3 MN·m/kg

Modulus of Resilience

21 kJ/m³
2 kJ/m³

Thermal Diffusivity

13.3 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

2
1

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 scaleBi58Sn42Field's Metal

Manufacturing and finishing

CapabilityBi58Sn42Field's Metal
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Bi58Sn42 vs Field's Metal — frequently asked

Is Bi58Sn42 stronger than Field's Metal?

Yes. Bi58Sn42 has a typical yield strength of 42 MPa (6.09 ksi) against 6 MPa (0.87 ksi) for Field's Metal — about 7.0 times as much. Tensile strength is 65 MPa (9.43 ksi) vs 11 MPa (1.6 ksi).

Which is cheaper, Bi58Sn42 or Field'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.

When should I choose Bi58Sn42 over Field's Metal?

Pick Bi58Sn42 when strength drives the design, or when surface hardness matters. Pick Field's Metal when weight is the constraint.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Bi58Sn42 and Field'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.