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Solder & Low-Melting Alloy Sn63Pb37 vs Sn63Pb37Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn63Pb37 and Sn63Pb37Sb are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 27 MPa (3.92 ksi) for Sn63Pb37, about 41% more; tensile strength follows at 58 MPa (8.41 ksi) vs 46 MPa (6.67 ksi). Sn63Pb37Sb is harder — 16 HB against 13 HB for Sn63Pb37 — which matters for wear surfaces and threads. Sn63Pb37Sb is stiffer (32 GPa vs 30 GPa).

Sn63Pb37SbChoose it when strength drives the design, or when surface hardness matters.

Sn63Pb37 vs Sn63Pb37Sb: properties

Sn63Pb37Sn63Pb37Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

30 GPa4.4 Msi
32 GPa4.6 Msi

Shear Modulus

11 GPa1.6 Msi
12.5 GPa1.8 Msi

Tensile Strength (Ultimate)

46 MPa6.7 ksi
58 MPa8.4 ksi

Yield Strength (0.2% offset)

27 MPa3.9 ksi
38 MPa5.5 ksi

Elongation at Break

35%
32%

Shear Strength

33 MPa4.8 ksi
38 MPa5.5 ksi

Fatigue Strength (Endurance Limit)

12 MPa1.7 ksi
15 MPa2.2 ksi

Hardness, Brinell

13 HB
16 HB

Hardness, Vickers

15 HV
—

Same in both: Bulk Modulus 50 GPa7.3 Msi · Poisson's Ratio 0.4

Physical

Density and transition temperatures.

Liquidus Temperature

183°C361 °F
185°C365 °F

Same in both: Density 8.4 g/cm³0.3 lb/in³ · Melting Point (Solidus) 183°C361 °F

Thermal

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

25 µm/m·K13.9 µin/in·°F
24.5 µm/m·K13.6 µin/in·°F

Same in both: Thermal Conductivity 50 W/m·K28.9 BTU/hr·ft·°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.

Electrical Conductivity

11.9 % IACS
11.5 % IACS

Electrical Resistivity

1.45×10⁻⁷ Ω·m5.71 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)

-0.51 V
-0.5 V

Corrosion Resistance

45 / 100
40 / 100

Manufacturability

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

Machinability

25 / 100
20 / 100

Formability (cold)

95 / 100
90 / 100

Weldability

—
20 / 100

Same in both: Castability 95 / 100 · Brazeability / Solderability 100 / 100 · Polishability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

500 L/kg59.9 gal/lb
320 L/kg38.3 gal/lb

Typical Recycled Content

40%
30%

Same in both: Embodied Energy (primary production) 210 MJ/kg90,284 BTU/lb · Embodied Carbon (primary production) 11 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

5 kN·m/kg
7 kN·m/kg

Specific Stiffness (E / density)

3.6 MN·m/kg
3.8 MN·m/kg

Modulus of Resilience

12 kJ/m³
23 kJ/m³

Thermal Diffusivity

35.6 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 scaleSn63Pb37Sn63Pb37Sb

Manufacturing and finishing

CapabilitySn63Pb37Sn63Pb37Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn63Pb37 vs Sn63Pb37Sb — frequently asked

Is Sn63Pb37Sb stronger than Sn63Pb37?

Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 27 MPa (3.92 ksi) for Sn63Pb37 — about 41% more. Tensile strength is 58 MPa (8.41 ksi) vs 46 MPa (6.67 ksi).

Which is cheaper, Sn63Pb37 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, Sn63Pb37 or Sn63Pb37Sb?

Sn63Pb37, by a small margin. Both rate poor for machinability — 25/100 against 20/100 for Sn63Pb37Sb.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn63Pb37 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.