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Solder & Low-Melting Alloy Sn60Pb38Bi2 vs Sn63Pb37Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn60Pb38Bi2 and Sn63Pb37Sb are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 30 MPa (4.35 ksi) for Sn60Pb38Bi2, about 27% more; tensile strength follows at 58 MPa (8.41 ksi) vs 50 MPa (7.25 ksi). In exchange, Sn60Pb38Bi2 is the more ductile: elongation 40% versus 32% for Sn63Pb37Sb, and Sn63Pb37Sb is harder (16 HB vs 15 HB). Sn63Pb37Sb is stiffer (32 GPa vs 30 GPa). On the shop floor, Sn60Pb38Bi2 machines more easily (30 vs 20 out of 100).

Sn60Pb38Bi2Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

Sn63Pb37SbChoose it when strength drives the design.

Sn60Pb38Bi2 vs Sn63Pb37Sb: properties

Sn60Pb38Bi2Sn63Pb37Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

30 GPa4.4 Msi
32 GPa4.6 Msi

Shear Modulus

10.7 GPa1.6 Msi
12.5 GPa1.8 Msi

Bulk Modulus

48 GPa7 Msi
50 GPa7.3 Msi

Tensile Strength (Ultimate)

50 MPa7.3 ksi
58 MPa8.4 ksi

Yield Strength (0.2% offset)

30 MPa4.4 ksi
38 MPa5.5 ksi

Elongation at Break

40%
32%

Compressive Strength

55 MPa8 ksi
—

Shear Strength

33 MPa4.8 ksi
38 MPa5.5 ksi

Fatigue Strength (Endurance Limit)

20 MPa2.9 ksi
15 MPa2.2 ksi

Hardness, Brinell

15 HB
16 HB

Same in both: Poisson's Ratio 0.4

Physical

Density and transition temperatures.

Density

8.5 g/cm³0.31 lb/in³
8.4 g/cm³0.3 lb/in³

Melting Point (Solidus)

178°C352 °F
183°C361 °F

Liquidus Temperature

190°C374 °F
185°C365 °F

Thermal

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

Specific Heat Capacity

180 J/kg·K0.04 BTU/lb·°F
170 J/kg·K0.04 BTU/lb·°F

Same in both: Thermal Conductivity 50 W/m·K28.9 BTU/hr·ft·°F · Thermal Expansion (CTE, 20–100 °C) 24.5 µm/m·K13.6 µin/in·°F · Latent Heat of Fusion 42 J/g18.1 BTU/lb · Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -55°C-67 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 11.5 % IACS · Electrical Resistivity 1.5×10⁻⁷ Ω·m5.91 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

45 / 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

30 / 100
20 / 100

Brazeability / Solderability

98 / 100
100 / 100

Weldability

—
20 / 100

Polishability

—
25 / 100

Same in both: Formability (cold) 90 / 100 · Castability 95 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

190 MJ/kg81,685 BTU/lb
210 MJ/kg90,284 BTU/lb

Embodied Carbon (primary production)

10.3 kg CO₂/kg
11 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
320 L/kg38.3 gal/lb

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

6 kN·m/kg
7 kN·m/kg

Specific Stiffness (E / density)

3.5 MN·m/kg
3.8 MN·m/kg

Modulus of Resilience

15 kJ/m³
23 kJ/m³

Thermal Diffusivity

32.7 mm²/s
35 mm²/s

Thermal Shock Resistance Index

3
4

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 scaleSn63Pb37SbSn60Pb38Bi2

Manufacturing and finishing

CapabilitySn60Pb38Bi2Sn63Pb37Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn60Pb38Bi2 vs Sn63Pb37Sb — frequently asked

Is Sn63Pb37Sb stronger than Sn60Pb38Bi2?

Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 30 MPa (4.35 ksi) for Sn60Pb38Bi2 — about 27% more. Tensile strength is 58 MPa (8.41 ksi) vs 50 MPa (7.25 ksi).

Which is cheaper, Sn60Pb38Bi2 or Sn63Pb37Sb?

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, Sn60Pb38Bi2 or Sn63Pb37Sb?

Sn60Pb38Bi2, by a small margin. Both rate poor for machinability — 30/100 against 20/100 for Sn63Pb37Sb.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn60Pb38Bi2 and Sn63Pb37Sb 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.