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Solder & Low-Melting Alloy Pb49Sn48Bi3 vs Pb60Sn40

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Pb49Sn48Bi3 and Pb60Sn40 are both solder & low-melting alloy grades. Pb49Sn48Bi3 is the stronger of the two: yield strength 28 MPa (4.06 ksi) against 24 MPa (3.48 ksi) for Pb60Sn40, about 17% more; tensile strength follows at 45 MPa (6.53 ksi) vs 38 MPa (5.51 ksi). Pb49Sn48Bi3 is harder — 14 HB against 12 HB for Pb60Sn40 — which matters for wear surfaces and threads. Pb49Sn48Bi3 is lighter (8.9 g/cm³ vs 9.29 g/cm³ for Pb60Sn40) and Pb49Sn48Bi3 is stiffer (30 GPa vs 24 GPa).

Pb49Sn48Bi3Choose it when strength drives the design, or when surface hardness matters.

Pb49Sn48Bi3 vs Pb60Sn40: properties

Pb49Sn48Bi3Pb60Sn40

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

30 GPa4.4 Msi
24 GPa3.5 Msi

Shear Modulus

11 GPa1.6 Msi
9 GPa1.3 Msi

Bulk Modulus

45 GPa6.5 Msi
33 GPa4.8 Msi

Tensile Strength (Ultimate)

45 MPa6.5 ksi
38 MPa5.5 ksi

Yield Strength (0.2% offset)

28 MPa4.1 ksi
24 MPa3.5 ksi

Shear Strength

33 MPa4.8 ksi
28 MPa4.1 ksi

Fatigue Strength (Endurance Limit)

14 MPa2 ksi
12 MPa1.7 ksi

Hardness, Brinell

14 HB
12 HB

Hardness, Vickers

14 HV
—

Same in both: Poisson's Ratio 0.4 · Elongation at Break 40%

Physical

Density and transition temperatures.

Density

8.9 g/cm³0.32 lb/in³
9.29 g/cm³0.34 lb/in³

Melting Point (Solidus)

178°C352 °F
183°C361 °F

Liquidus Temperature

210°C410 °F
238°C460 °F

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

24 µm/m·K13.3 µin/in·°F
24.5 µm/m·K13.6 µin/in·°F

Latent Heat of Fusion

42 J/g18.1 BTU/lb
41 J/g17.6 BTU/lb

Same in both: Specific Heat Capacity 176 J/kg·K0.04 BTU/lb·°F · Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -55°C-67 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

11 % IACS
10.1 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

35 / 100
40 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.5 V

Manufacturability

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

Machinability

25 / 100
30 / 100

Polishability

20 / 100
30 / 100

Same in both: Weldability 20 / 100 · Formability (cold) 90 / 100 · Castability 90 / 100 · Brazeability / Solderability 95 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

135 MJ/kg58,040 BTU/lb
145 MJ/kg62,339 BTU/lb

Embodied Carbon (primary production)

8.5 kg CO₂/kg
7.6 kg CO₂/kg

Typical Recycled Content

35%
55%

Same in both: Embodied Water 300 L/kg35.9 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

5 kN·m/kg
4 kN·m/kg

Specific Stiffness (E / density)

3.4 MN·m/kg
2.6 MN·m/kg

Modulus of Resilience

13 kJ/m³
12 kJ/m³

Thermal Diffusivity

29.4 mm²/s
26.9 mm²/s

Same in both: Thermal Shock Resistance Index 3

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 scalePb60Sn40Pb49Sn48Bi3

Manufacturing and finishing

CapabilityPb49Sn48Bi3Pb60Sn40
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Pb49Sn48Bi3 vs Pb60Sn40 — frequently asked

Is Pb49Sn48Bi3 stronger than Pb60Sn40?

Yes. Pb49Sn48Bi3 has a typical yield strength of 28 MPa (4.06 ksi) against 24 MPa (3.48 ksi) for Pb60Sn40 — about 17% more. Tensile strength is 45 MPa (6.53 ksi) vs 38 MPa (5.51 ksi).

Which is cheaper, Pb49Sn48Bi3 or Pb60Sn40?

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, Pb49Sn48Bi3 or Pb60Sn40?

Pb60Sn40, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for Pb49Sn48Bi3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Pb49Sn48Bi3 and Pb60Sn40 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.