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Solder & Low-Melting Alloy Sn50Pb32Cd18 vs Sn60Pb40Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn50Pb32Cd18 and Sn60Pb40Sb are both solder & low-melting alloy grades. Sn60Pb40Sb is the stronger of the two: yield strength 32 MPa (4.64 ksi) against 25 MPa (3.63 ksi) for Sn50Pb32Cd18, about 28% more; tensile strength follows at 52 MPa (7.54 ksi) vs 45 MPa (6.53 ksi). Sn60Pb40Sb is harder — 15 HB against 14 HB for Sn50Pb32Cd18 — which matters for wear surfaces and threads. Sn60Pb40Sb is stiffer (31 GPa vs 28 GPa) and Sn60Pb40Sb runs hotter in service (110°C vs 70°C continuous). On the shop floor, Sn50Pb32Cd18 welds better (poor vs not recommended).

Sn50Pb32Cd18Choose it when it will be welded.

Sn60Pb40SbChoose it when strength drives the design, or when surface hardness matters.

Sn50Pb32Cd18 vs Sn60Pb40Sb: properties

Sn50Pb32Cd18Sn60Pb40Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

28 GPa4.1 Msi
31 GPa4.5 Msi

Shear Modulus

10.5 GPa1.5 Msi
11.5 GPa1.7 Msi

Bulk Modulus

38 GPa5.5 Msi
42 GPa6.1 Msi

Poisson's Ratio

0.36
0.38

Tensile Strength (Ultimate)

45 MPa6.5 ksi
52 MPa7.5 ksi

Yield Strength (0.2% offset)

25 MPa3.6 ksi
32 MPa4.6 ksi

Shear Strength

30 MPa4.4 ksi
38 MPa5.5 ksi

Fatigue Strength (Endurance Limit)

14 MPa2 ksi
15 MPa2.2 ksi

Hardness, Brinell

14 HB
15 HB

Charpy V-Notch Impact (RT)

—
6 J4.4 ft·lbf

Hardness, Vickers

—
16 HV

Same in both: Elongation at Break 35%

Physical

Density and transition temperatures.

Melting Point (Solidus)

145°C293 °F
183°C361 °F

Liquidus Temperature

145°C293 °F
190°C374 °F

Same in both: Density 8.5 g/cm³0.31 lb/in³

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Specific Heat Capacity

185 J/kg·K0.04 BTU/lb·°F
176 J/kg·K0.04 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

27 µm/m·K15 µin/in·°F
24.5 µm/m·K13.6 µin/in·°F

Latent Heat of Fusion

40 J/g17.2 BTU/lb
43 J/g18.5 BTU/lb

Max Service Temperature (continuous)

70°C158 °F
110°C230 °F

Min Service Temperature

-60°C-76 °F
-55°C-67 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
11.5 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 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)

-0.55 V
-0.5 V

Corrosion Resistance

35 / 100
45 / 100

Manufacturability

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

Machinability

30 / 100
35 / 100

Weldability

20 / 100
10 / 100

Formability (cold)

90 / 100
85 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

95 / 100
92 / 100

Same in both: Polishability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

180 MJ/kg77,386 BTU/lb
190 MJ/kg81,685 BTU/lb

Embodied Carbon (primary production)

9.8 kg CO₂/kg
10.3 kg CO₂/kg

Typical Recycled Content

25%
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)

3.3 MN·m/kg
3.6 MN·m/kg

Modulus of Resilience

11 kJ/m³
17 kJ/m³

Thermal Diffusivity

28.6 mm²/s
33.4 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 scaleSn60Pb40SbSn50Pb32Cd18

Manufacturing and finishing

CapabilitySn50Pb32Cd18Sn60Pb40Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn50Pb32Cd18 vs Sn60Pb40Sb — frequently asked

Is Sn60Pb40Sb stronger than Sn50Pb32Cd18?

Yes. Sn60Pb40Sb has a typical yield strength of 32 MPa (4.64 ksi) against 25 MPa (3.63 ksi) for Sn50Pb32Cd18 — about 28% more. Tensile strength is 52 MPa (7.54 ksi) vs 45 MPa (6.53 ksi).

Which is cheaper, Sn50Pb32Cd18 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, Sn50Pb32Cd18 or Sn60Pb40Sb?

Sn60Pb40Sb. Its machinability rates fair (35/100) against poor (30/100) for Sn50Pb32Cd18; for welding the order is Sn50Pb32Cd18 first (poor, 20/100) then Sn60Pb40Sb (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn50Pb32Cd18 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.