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Solder & Low-Melting Alloy Pb50Sn50 vs Pb97.5Ag1.5Sn1

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Pb50Sn50 and Pb97.5Ag1.5Sn1 are both solder & low-melting alloy grades. Pb50Sn50 is the stronger of the two: yield strength 27 MPa (3.92 ksi) against 15 MPa (2.18 ksi) for Pb97.5Ag1.5Sn1, about 80% more; tensile strength follows at 42 MPa (6.09 ksi) vs 25 MPa (3.63 ksi). Pb50Sn50 is the more ductile: elongation 55% versus 40% for Pb97.5Ag1.5Sn1, and Pb50Sn50 is harder (14 HB vs 10 HB). Pb50Sn50 is lighter (8.85 g/cm³ vs 11.28 g/cm³ for Pb97.5Ag1.5Sn1) and Pb50Sn50 is stiffer (23 GPa vs 16.5 GPa).

Pb50Sn50Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Pb97.5Ag1.5Sn1Choose it when the part sees heat.

Pb50Sn50 vs Pb97.5Ag1.5Sn1: properties

Pb50Sn50Pb97.5Ag1.5Sn1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

23 GPa3.3 Msi
16.5 GPa2.4 Msi

Shear Modulus

8.5 GPa1.2 Msi
5.9 GPa0.86 Msi

Bulk Modulus

36 GPa5.2 Msi
42 GPa6.1 Msi

Poisson's Ratio

0.4
0.42

Tensile Strength (Ultimate)

42 MPa6.1 ksi
25 MPa3.6 ksi

Yield Strength (0.2% offset)

27 MPa3.9 ksi
15 MPa2.2 ksi

Elongation at Break

55%
40%

Shear Strength

34 MPa4.9 ksi
19 MPa2.8 ksi

Fatigue Strength (Endurance Limit)

14 MPa2 ksi
8 MPa1.2 ksi

Hardness, Brinell

14 HB
10 HB

Hardness, Vickers

13 HV
—

Physical

Density and transition temperatures.

Density

8.85 g/cm³0.32 lb/in³
11.28 g/cm³0.41 lb/in³

Melting Point (Solidus)

183°C361 °F
309°C588 °F

Liquidus Temperature

216°C421 °F
309°C588 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
33 W/m·K19.1 BTU/hr·ft·°F

Specific Heat Capacity

176 J/kg·K0.04 BTU/lb·°F
130 J/kg·K0.03 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

24.5 µm/m·K13.6 µin/in·°F
29 µm/m·K16.1 µin/in·°F

Latent Heat of Fusion

42 J/g18.1 BTU/lb
25 J/g10.7 BTU/lb

Max Service Temperature (continuous)

100°C212 °F
200°C392 °F

Min Service Temperature

-60°C-76 °F
-55°C-67 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.9 % IACS
7.5 % IACS

Electrical Resistivity

1.58×10⁻⁷ Ω·m6.22 µΩ·in
2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.32 V
-0.53 V

Corrosion Resistance

45 / 100
40 / 100

Manufacturability

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

Machinability

30 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
—

Weldability

15 / 100
20 / 100

Formability (cold)

95 / 100
92 / 100

Castability

90 / 100
88 / 100

Brazeability / Solderability

98 / 100
85 / 100

Same in both: Polishability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

160 MJ/kg68,788 BTU/lb
45 MJ/kg19,347 BTU/lb

Embodied Carbon (primary production)

10.5 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

450 L/kg53.9 gal/lb
120 L/kg14.4 gal/lb

Typical Recycled Content

45%
55%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

5 kN·m/kg
2 kN·m/kg

Specific Stiffness (E / density)

2.6 MN·m/kg
1.5 MN·m/kg

Modulus of Resilience

16 kJ/m³
7 kJ/m³

Thermal Diffusivity

32.1 mm²/s
22.5 mm²/s

Thermal Shock Resistance Index

4
2

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 scalePb50Sn50Pb97.5Ag1.5Sn1

Manufacturing and finishing

CapabilityPb50Sn50Pb97.5Ag1.5Sn1
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Pb50Sn50 vs Pb97.5Ag1.5Sn1 — frequently asked

Is Pb50Sn50 stronger than Pb97.5Ag1.5Sn1?

Yes. Pb50Sn50 has a typical yield strength of 27 MPa (3.92 ksi) against 15 MPa (2.18 ksi) for Pb97.5Ag1.5Sn1 — about 80% more. Tensile strength is 42 MPa (6.09 ksi) vs 25 MPa (3.63 ksi).

Which is cheaper, Pb50Sn50 or Pb97.5Ag1.5Sn1?

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, Pb50Sn50 or Pb97.5Ag1.5Sn1?

Pb50Sn50, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for Pb97.5Ag1.5Sn1; for welding the order is Pb97.5Ag1.5Sn1 first (poor, 20/100) then Pb50Sn50 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Pb50Sn50 and Pb97.5Ag1.5Sn1 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.