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Solder & Low-Melting Alloy Bi58Sn42 vs In97Ag3

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Bi58Sn42 and In97Ag3 are both solder & low-melting alloy grades. Bi58Sn42 is the stronger of the two: yield strength 42 MPa (6.09 ksi) against 3 MPa (0.435 ksi) for In97Ag3, about 14 times as much; tensile strength follows at 65 MPa (9.43 ksi) vs 6 MPa (0.87 ksi). In exchange, In97Ag3 is the more ductile: elongation 55% versus 40% for Bi58Sn42, and Bi58Sn42 is harder (22 HB vs 1 HB). In97Ag3 is lighter (7.38 g/cm³ vs 8.56 g/cm³ for Bi58Sn42) and Bi58Sn42 is stiffer (42 GPa vs 11 GPa). On the shop floor, Bi58Sn42 machines more easily (poor vs not recommended).

Bi58Sn42Choose it when strength drives the design, or when the part sees heat.

In97Ag3Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

Bi58Sn42 vs In97Ag3: properties

Bi58Sn42In97Ag3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

42 GPa6.1 Msi
11 GPa1.6 Msi

Shear Modulus

16 GPa2.3 Msi
3.8 GPa0.55 Msi

Poisson's Ratio

0.33
0.45

Tensile Strength (Ultimate)

65 MPa9.4 ksi
6 MPa0.87 ksi

Yield Strength (0.2% offset)

42 MPa6.1 ksi
3 MPa0.44 ksi

Elongation at Break

40%
55%

Shear Strength

45 MPa6.5 ksi
6 MPa0.87 ksi

Fatigue Strength (Endurance Limit)

20 MPa2.9 ksi
—

Hardness, Brinell

22 HB
1 HB

Hardness, Vickers

23 HV
—

Same in both: Bulk Modulus 41 GPa5.9 Msi

Physical

Density and transition temperatures.

Density

8.56 g/cm³0.31 lb/in³
7.38 g/cm³0.27 lb/in³

Melting Point (Solidus)

138°C280 °F
143°C289 °F

Liquidus Temperature

138°C280 °F
143°C289 °F

Thermal

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

Thermal Conductivity

19 W/m·K11 BTU/hr·ft·°F
73 W/m·K42.2 BTU/hr·ft·°F

Specific Heat Capacity

167 J/kg·K0.04 BTU/lb·°F
232 J/kg·K0.06 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
30 µm/m·K16.7 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
60°C140 °F

Min Service Temperature

-40°C-40 °F
-269°C-452 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5 % IACS
18 % IACS

Electrical Resistivity

3.4×10⁻⁷ Ω·m13.4 µΩ·in
9.4×10⁻⁸ Ω·m3.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.45 V
—

Corrosion Resistance

50 / 100
45 / 100

Manufacturability

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

Machinability

30 / 100
8 / 100

Weldability

20 / 100
25 / 100

Formability (cold)

60 / 100
98 / 100

Castability

90 / 100
80 / 100

Brazeability / Solderability

95 / 100
97 / 100

Polishability

30 / 100
15 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

190 MJ/kg81,685 BTU/lb
1,800 MJ/kg773,861 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
110 kg CO₂/kg

Embodied Water

500 L/kg59.9 gal/lb
—

Typical Recycled Content

25%
35%

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
1.5 MN·m/kg

Modulus of Resilience

21 kJ/m³
0 kJ/m³

Thermal Diffusivity

13.3 mm²/s
42.6 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 scaleBi58Sn42In97Ag3

Manufacturing and finishing

CapabilityBi58Sn42In97Ag3
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Bi58Sn42 vs In97Ag3 — frequently asked

Is Bi58Sn42 stronger than In97Ag3?

Yes. Bi58Sn42 has a typical yield strength of 42 MPa (6.09 ksi) against 3 MPa (0.435 ksi) for In97Ag3 — about 14 times as much. Tensile strength is 65 MPa (9.43 ksi) vs 6 MPa (0.87 ksi).

Which is cheaper, Bi58Sn42 or In97Ag3?

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 In97Ag3?

Bi58Sn42. Its machinability rates poor (30/100) against not recommended (8/100) for In97Ag3; for welding the order is In97Ag3 first (poor, 25/100) then Bi58Sn42 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Bi58Sn42 and In97Ag3 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.