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Solder & Low-Melting Alloy Sn63Pb37Sb vs Sn95Sb5

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Sn63Pb37Sb and Sn95Sb5 are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 30 MPa (4.35 ksi) for Sn95Sb5, about 27% more; tensile strength follows at 58 MPa (8.41 ksi) vs 40 MPa (5.8 ksi). In exchange, Sn95Sb5 is the more ductile: elongation 38% versus 32% for Sn63Pb37Sb, and Sn63Pb37Sb is harder (16 HB vs 13 HB). Sn95Sb5 is lighter (7.25 g/cm³ vs 8.4 g/cm³ for Sn63Pb37Sb) and Sn95Sb5 is stiffer (48 GPa vs 32 GPa). On the shop floor, Sn95Sb5 machines more easily (30 vs 20 out of 100).

Sn63Pb37SbChoose it when strength drives the design.

Sn95Sb5Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

Sn63Pb37Sb vs Sn95Sb5: properties

Sn63Pb37SbSn95Sb5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

32 GPa4.6 Msi
48 GPa7 Msi

Shear Modulus

12.5 GPa1.8 Msi
18 GPa2.6 Msi

Bulk Modulus

50 GPa7.3 Msi
55 GPa8 Msi

Poisson's Ratio

0.4
0.35

Tensile Strength (Ultimate)

58 MPa8.4 ksi
40 MPa5.8 ksi

Yield Strength (0.2% offset)

38 MPa5.5 ksi
30 MPa4.4 ksi

Elongation at Break

32%
38%

Fatigue Strength (Endurance Limit)

15 MPa2.2 ksi
18 MPa2.6 ksi

Hardness, Brinell

16 HB
13 HB

Same in both: Shear Strength 38 MPa5.5 ksi

Physical

Density and transition temperatures.

Density

8.4 g/cm³0.3 lb/in³
7.25 g/cm³0.26 lb/in³

Melting Point (Solidus)

183°C361 °F
235°C455 °F

Liquidus Temperature

185°C365 °F
240°C464 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
28 W/m·K16.2 BTU/hr·ft·°F

Specific Heat Capacity

170 J/kg·K0.04 BTU/lb·°F
220 J/kg·K0.05 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

42 J/g18.1 BTU/lb
60 J/g25.8 BTU/lb

Max Service Temperature (continuous)

100°C212 °F
150°C302 °F

Min Service Temperature

-55°C-67 °F
-60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 11.5 % IACS · Electrical Resistivity 1.5×10⁻⁷ Ω·m5.91 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

40 / 100
55 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.5 V

Manufacturability

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

Machinability

20 / 100
30 / 100

Formability (cold)

90 / 100
88 / 100

Castability

95 / 100
85 / 100

Brazeability / Solderability

100 / 100
80 / 100

Polishability

25 / 100
35 / 100

Same in both: Weldability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

210 MJ/kg90,284 BTU/lb
320 MJ/kg137,575 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
18 kg CO₂/kg

Embodied Water

320 L/kg38.3 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

7 kN·m/kg
6 kN·m/kg

Specific Stiffness (E / density)

3.8 MN·m/kg
6.6 MN·m/kg

Modulus of Resilience

23 kJ/m³
9 kJ/m³

Thermal Diffusivity

35 mm²/s
17.6 mm²/s

Thermal Shock Resistance Index

4
1

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 scaleSn63Pb37SbSn95Sb5

Manufacturing and finishing

CapabilitySn63Pb37SbSn95Sb5
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Sn63Pb37Sb vs Sn95Sb5 — frequently asked

Is Sn63Pb37Sb stronger than Sn95Sb5?

Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 30 MPa (4.35 ksi) for Sn95Sb5 — about 27% more. Tensile strength is 58 MPa (8.41 ksi) vs 40 MPa (5.8 ksi).

Which is cheaper, Sn63Pb37Sb or Sn95Sb5?

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, Sn63Pb37Sb or Sn95Sb5?

Sn95Sb5, by a small margin. Both rate poor for machinability — 30/100 against 20/100 for Sn63Pb37Sb.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sn63Pb37Sb and Sn95Sb5 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.