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Solder & Low-Melting Alloy Sn50Pb50 vs Sn60Pb40Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn50Pb50 and Sn60Pb40Sb are both solder & low-melting alloy grades. Sn60Pb40Sb is the stronger of the two: yield strength 32 MPa (4.64 ksi) against 30 MPa (4.35 ksi) for Sn50Pb50, about 7% more; tensile strength follows at 52 MPa (7.54 ksi) vs 42 MPa (6.09 ksi). In exchange, Sn50Pb50 is the more ductile: elongation 45% versus 35% for Sn60Pb40Sb, and Sn60Pb40Sb is harder (15 HB vs 14 HB). Sn60Pb40Sb is lighter (8.5 g/cm³ vs 8.87 g/cm³ for Sn50Pb50) and Sn60Pb40Sb is stiffer (31 GPa vs 27 GPa). On the shop floor, Sn60Pb40Sb machines more easily (fair vs poor) and Sn50Pb50 welds better (poor vs not recommended).

Sn50Pb50Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

Sn60Pb40SbChoose it when strength drives the design, or when weight is the constraint.

Sn50Pb50 vs Sn60Pb40Sb: properties

Sn50Pb50Sn60Pb40Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

27 GPa3.9 Msi
31 GPa4.5 Msi

Shear Modulus

9.6 GPa1.4 Msi
11.5 GPa1.7 Msi

Bulk Modulus

45 GPa6.5 Msi
42 GPa6.1 Msi

Poisson's Ratio

0.4
0.38

Tensile Strength (Ultimate)

42 MPa6.1 ksi
52 MPa7.5 ksi

Yield Strength (0.2% offset)

30 MPa4.4 ksi
32 MPa4.6 ksi

Elongation at Break

45%
35%

Compressive Strength

45 MPa6.5 ksi
—

Shear Strength

35 MPa5.1 ksi
38 MPa5.5 ksi

Fatigue Strength (Endurance Limit)

14 MPa2 ksi
15 MPa2.2 ksi

Hardness, Brinell

14 HB
15 HB

Hardness, Vickers

13 HV
16 HV

Charpy V-Notch Impact (RT)

—
6 J4.4 ft·lbf

Physical

Density and transition temperatures.

Density

8.87 g/cm³0.32 lb/in³
8.5 g/cm³0.31 lb/in³

Liquidus Temperature

216°C421 °F
190°C374 °F

Same in both: Melting Point (Solidus) 183°C361 °F

Thermal

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

Thermal Conductivity

47 W/m·K27.2 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

100°C212 °F
110°C230 °F

Min Service Temperature

-60°C-76 °F
-55°C-67 °F

Same in both: Specific Heat Capacity 176 J/kg·K0.04 BTU/lb·°F · Latent Heat of Fusion 43 J/g18.5 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

10.9 % IACS
11.5 % IACS

Electrical Resistivity

1.58×10⁻⁷ Ω·m6.22 µΩ·in
1.5×10⁻⁷ Ω·m5.91 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.52 V
-0.5 V

Same in both: Corrosion Resistance 45 / 100

Manufacturability

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

Machinability

25 / 100
35 / 100

Weldability

20 / 100
10 / 100

Formability (cold)

90 / 100
85 / 100

Castability

92 / 100
95 / 100

Brazeability / Solderability

97 / 100
92 / 100

Polishability

30 / 100
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

170 MJ/kg73,087 BTU/lb
190 MJ/kg81,685 BTU/lb

Embodied Carbon (primary production)

9.5 kg CO₂/kg
10.3 kg CO₂/kg

Typical Recycled Content

40%
35%

Same in both: Embodied Water 320 L/kg38.3 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

5 kN·m/kg
6 kN·m/kg

Specific Stiffness (E / density)

3 MN·m/kg
3.6 MN·m/kg

Thermal Diffusivity

30.1 mm²/s
33.4 mm²/s

Same in both: Modulus of Resilience 17 kJ/m³ · 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 scaleSn60Pb40SbSn50Pb50

Manufacturing and finishing

CapabilitySn50Pb50Sn60Pb40Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn50Pb50 vs Sn60Pb40Sb — frequently asked

Is Sn60Pb40Sb stronger than Sn50Pb50?

Yes. Sn60Pb40Sb has a typical yield strength of 32 MPa (4.64 ksi) against 30 MPa (4.35 ksi) for Sn50Pb50 — about 7% more. Tensile strength is 52 MPa (7.54 ksi) vs 42 MPa (6.09 ksi).

Which is cheaper, Sn50Pb50 or Sn60Pb40Sb?

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, Sn50Pb50 or Sn60Pb40Sb?

Sn60Pb40Sb. Its machinability rates fair (35/100) against poor (25/100) for Sn50Pb50; for welding the order is Sn50Pb50 first (poor, 20/100) then Sn60Pb40Sb (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn50Pb50 and Sn60Pb40Sb 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.