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Solder & Low-Melting Alloy Sn60Pb40Sb vs Sn96Ag2.5Bi1Cu0.5

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn60Pb40Sb and Sn96Ag2.5Bi1Cu0.5 are both solder & low-melting alloy grades. Sn96Ag2.5Bi1Cu0.5 is the stronger of the two: yield strength 40 MPa (5.8 ksi) against 32 MPa (4.64 ksi) for Sn60Pb40Sb, about 25% more. In exchange, Sn60Pb40Sb is the more ductile: elongation 35% versus 30% for Sn96Ag2.5Bi1Cu0.5, and Sn60Pb40Sb is harder (16 HV vs 15 HV). Sn96Ag2.5Bi1Cu0.5 is lighter (7.4 g/cm³ vs 8.5 g/cm³ for Sn60Pb40Sb) and Sn96Ag2.5Bi1Cu0.5 is stiffer (48 GPa vs 31 GPa). On the shop floor, Sn60Pb40Sb machines more easily (fair vs poor).

Sn60Pb40SbChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

Sn96Ag2.5Bi1Cu0.5Choose it when strength drives the design, or when weight is the constraint.

Sn60Pb40Sb vs Sn96Ag2.5Bi1Cu0.5: properties

Sn60Pb40SbSn96Ag2.5Bi1Cu0.5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

31 GPa4.5 Msi
48 GPa7 Msi

Shear Modulus

11.5 GPa1.7 Msi
18 GPa2.6 Msi

Bulk Modulus

42 GPa6.1 Msi
58 GPa8.4 Msi

Poisson's Ratio

0.38
0.36

Yield Strength (0.2% offset)

32 MPa4.6 ksi
40 MPa5.8 ksi

Elongation at Break

35%
30%

Shear Strength

38 MPa5.5 ksi
32 MPa4.6 ksi

Fatigue Strength (Endurance Limit)

15 MPa2.2 ksi
20 MPa2.9 ksi

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
—

Hardness, Brinell

15 HB
—

Hardness, Vickers

16 HV
15 HV

Same in both: Tensile Strength (Ultimate) 52 MPa7.5 ksi

Physical

Density and transition temperatures.

Density

8.5 g/cm³0.31 lb/in³
7.4 g/cm³0.27 lb/in³

Melting Point (Solidus)

183°C361 °F
214°C417 °F

Liquidus Temperature

190°C374 °F
221°C430 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
56 W/m·K32.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

24.5 µm/m·K13.6 µin/in·°F
22 µm/m·K12.2 µin/in·°F

Latent Heat of Fusion

43 J/g18.5 BTU/lb
58 J/g24.9 BTU/lb

Max Service Temperature (continuous)

110°C230 °F
125°C257 °F

Same in both: Min Service Temperature -55°C-67 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

11.5 % IACS
12.5 % IACS

Electrical Resistivity

1.5×10⁻⁷ Ω·m5.91 µΩ·in
1.38×10⁻⁷ Ω·m5.43 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.5 V · Corrosion Resistance 45 / 100

Manufacturability

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

Machinability

35 / 100
25 / 100

Weldability

10 / 100
—

Formability (cold)

85 / 100
90 / 100

Castability

95 / 100
88 / 100

Brazeability / Solderability

92 / 100
97 / 100

Polishability

25 / 100
30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

190 MJ/kg81,685 BTU/lb
350 MJ/kg150,473 BTU/lb

Embodied Carbon (primary production)

10.3 kg CO₂/kg
22 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
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)

3.6 MN·m/kg
6.5 MN·m/kg

Thermal Diffusivity

33.4 mm²/s
32.6 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 scaleSn60Pb40SbSn96Ag2.5Bi1Cu0.5

Manufacturing and finishing

CapabilitySn60Pb40SbSn96Ag2.5Bi1Cu0.5
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn60Pb40Sb vs Sn96Ag2.5Bi1Cu0.5 — frequently asked

Is Sn96Ag2.5Bi1Cu0.5 stronger than Sn60Pb40Sb?

Yes. Sn96Ag2.5Bi1Cu0.5 has a typical yield strength of 40 MPa (5.8 ksi) against 32 MPa (4.64 ksi) for Sn60Pb40Sb — about 25% more. Tensile strength is 52 MPa (7.54 ksi) vs 52 MPa (7.54 ksi).

Which is cheaper, Sn60Pb40Sb or Sn96Ag2.5Bi1Cu0.5?

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, Sn60Pb40Sb or Sn96Ag2.5Bi1Cu0.5?

Sn60Pb40Sb. Its machinability rates fair (35/100) against poor (25/100) for Sn96Ag2.5Bi1Cu0.5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn60Pb40Sb and Sn96Ag2.5Bi1Cu0.5 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.