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Solder & Low-Melting Alloy SN100C vs Sn63Pb37Sb

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy SN100C and Sn63Pb37Sb are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 20 MPa (2.9 ksi) for SN100C, about 90% more; tensile strength follows at 58 MPa (8.41 ksi) vs 32 MPa (4.64 ksi). In exchange, SN100C is the more ductile: elongation 40% versus 32% for Sn63Pb37Sb, and Sn63Pb37Sb is harder (16 HB vs 15 HB). SN100C is lighter (7.4 g/cm³ vs 8.4 g/cm³ for Sn63Pb37Sb) and SN100C is stiffer (45 GPa vs 32 GPa).

SN100CChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

Sn63Pb37SbChoose it when strength drives the design.

SN100C vs Sn63Pb37Sb: properties

SN100CSn63Pb37Sb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

45 GPa6.5 Msi
32 GPa4.6 Msi

Shear Modulus

17 GPa2.5 Msi
12.5 GPa1.8 Msi

Bulk Modulus

52 GPa7.5 Msi
50 GPa7.3 Msi

Poisson's Ratio

0.36
0.4

Tensile Strength (Ultimate)

32 MPa4.6 ksi
58 MPa8.4 ksi

Yield Strength (0.2% offset)

20 MPa2.9 ksi
38 MPa5.5 ksi

Elongation at Break

40%
32%

Shear Strength

27 MPa3.9 ksi
38 MPa5.5 ksi

Hardness, Brinell

15 HB
16 HB

Hardness, Vickers

14 HV
—

Same in both: Fatigue Strength (Endurance Limit) 15 MPa2.2 ksi

Physical

Density and transition temperatures.

Density

7.4 g/cm³0.27 lb/in³
8.4 g/cm³0.3 lb/in³

Melting Point (Solidus)

227°C441 °F
183°C361 °F

Liquidus Temperature

227°C441 °F
185°C365 °F

Thermal

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

Thermal Conductivity

64 W/m·K37 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

23 µm/m·K12.8 µin/in·°F
24.5 µm/m·K13.6 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

125°C257 °F
100°C212 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

13 % IACS
11.5 % IACS

Electrical Resistivity

1.35×10⁻⁷ Ω·m5.31 µΩ·in
1.5×10⁻⁷ Ω·m5.91 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

45 / 100
40 / 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

25 / 100
20 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

92 / 100
100 / 100

Polishability

30 / 100
25 / 100

Same in both: Weldability 20 / 100 · Formability (cold) 90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

250 MJ/kg107,481 BTU/lb
210 MJ/kg90,284 BTU/lb

Embodied Carbon (primary production)

17 kg CO₂/kg
11 kg CO₂/kg

Embodied Water

600 L/kg71.9 gal/lb
320 L/kg38.3 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

4 kN·m/kg
7 kN·m/kg

Specific Stiffness (E / density)

6.1 MN·m/kg
3.8 MN·m/kg

Modulus of Resilience

4 kJ/m³
23 kJ/m³

Thermal Diffusivity

37.6 mm²/s
35 mm²/s

Thermal Shock Resistance Index

2
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 scaleSn63Pb37SbSN100C

Manufacturing and finishing

CapabilitySN100CSn63Pb37Sb
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

SN100C vs Sn63Pb37Sb — frequently asked

Is Sn63Pb37Sb stronger than SN100C?

Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 20 MPa (2.9 ksi) for SN100C — about 90% more. Tensile strength is 58 MPa (8.41 ksi) vs 32 MPa (4.64 ksi).

Which is cheaper, SN100C 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, SN100C or Sn63Pb37Sb?

SN100C, 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 SN100C 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.