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Solder & Low-Melting Alloy Sn30Pb70 vs Sn60Pb40Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn30Pb70 and Sn60Pb40Sb are both solder & low-melting alloy grades. Sn60Pb40Sb is the stronger of the two: yield strength 32 MPa (4.64 ksi) against 22 MPa (3.19 ksi) for Sn30Pb70, about 45% more; tensile strength follows at 52 MPa (7.54 ksi) vs 35 MPa (5.08 ksi). In exchange, Sn30Pb70 is the more ductile: elongation 45% versus 35% for Sn60Pb40Sb, and Sn60Pb40Sb is harder (15 HB vs 11 HB). Sn60Pb40Sb is lighter (8.5 g/cm³ vs 9.7 g/cm³ for Sn30Pb70) and Sn60Pb40Sb is stiffer (31 GPa vs 25 GPa).

Sn30Pb70Choose it when the part is bent, formed or impact-loaded.

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

Sn30Pb70 vs Sn60Pb40Sb: properties

Sn30Pb70Sn60Pb40Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

25 GPa3.6 Msi
31 GPa4.5 Msi

Shear Modulus

9 GPa1.3 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)

35 MPa5.1 ksi
52 MPa7.5 ksi

Yield Strength (0.2% offset)

22 MPa3.2 ksi
32 MPa4.6 ksi

Elongation at Break

45%
35%

Shear Strength

27 MPa3.9 ksi
38 MPa5.5 ksi

Fatigue Strength (Endurance Limit)

12 MPa1.7 ksi
15 MPa2.2 ksi

Hardness, Brinell

11 HB
15 HB

Charpy V-Notch Impact (RT)

—
6 J4.4 ft·lbf

Hardness, Vickers

—
16 HV

Physical

Density and transition temperatures.

Density

9.7 g/cm³0.35 lb/in³
8.5 g/cm³0.31 lb/in³

Liquidus Temperature

255°C491 °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

44 W/m·K25.4 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Specific Heat Capacity

160 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

35 J/g15 BTU/lb
43 J/g18.5 BTU/lb

Max Service Temperature (continuous)

100°C212 °F
110°C230 °F

Min Service Temperature

-60°C-76 °F
-55°C-67 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.3 % IACS
11.5 % IACS

Electrical Resistivity

1.85×10⁻⁷ Ω·m7.28 µΩ·in
1.5×10⁻⁷ Ω·m5.91 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.

Formability (cold)

90 / 100
85 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

95 / 100
92 / 100

Polishability

30 / 100
25 / 100

Weldability

—
10 / 100

Same in both: Machinability 35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
190 MJ/kg81,685 BTU/lb

Embodied Carbon (primary production)

6 kg CO₂/kg
10.3 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
320 L/kg38.3 gal/lb

Typical Recycled Content

45%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

4 kN·m/kg
6 kN·m/kg

Specific Stiffness (E / density)

2.6 MN·m/kg
3.6 MN·m/kg

Modulus of Resilience

10 kJ/m³
17 kJ/m³

Thermal Diffusivity

28.4 mm²/s
33.4 mm²/s

Thermal Shock Resistance Index

2
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 scaleSn60Pb40SbSn30Pb70

Manufacturing and finishing

CapabilitySn30Pb70Sn60Pb40Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn30Pb70 vs Sn60Pb40Sb — frequently asked

Is Sn60Pb40Sb stronger than Sn30Pb70?

Yes. Sn60Pb40Sb has a typical yield strength of 32 MPa (4.64 ksi) against 22 MPa (3.19 ksi) for Sn30Pb70 — about 45% more. Tensile strength is 52 MPa (7.54 ksi) vs 35 MPa (5.08 ksi).

Which is cheaper, Sn30Pb70 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.

When should I choose Sn30Pb70 over Sn60Pb40Sb?

Pick Sn30Pb70 when the part is bent, formed or impact-loaded. Pick Sn60Pb40Sb when strength drives the design, or when weight is the constraint.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn30Pb70 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.