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Solder & Low-Melting Alloy Pb65Sn35 vs Pb97.5Ag1.5Sn1

Solder & Low-Melting Alloy · grade comparison

Solder & Low-Melting Alloy Pb65Sn35 and Pb97.5Ag1.5Sn1 are both solder & low-melting alloy grades. Pb65Sn35 is the stronger of the two: yield strength 21 MPa (3.05 ksi) against 15 MPa (2.18 ksi) for Pb97.5Ag1.5Sn1, about 40% more; tensile strength follows at 33 MPa (4.79 ksi) vs 25 MPa (3.63 ksi). Pb65Sn35 is the more ductile: elongation 55% versus 40% for Pb97.5Ag1.5Sn1, and Pb65Sn35 is harder (12 HB vs 10 HB). Pb65Sn35 is lighter (9.5 g/cm³ vs 11.28 g/cm³ for Pb97.5Ag1.5Sn1) and Pb65Sn35 is stiffer (26 GPa vs 16.5 GPa).

Pb65Sn35Choose 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.

Pb65Sn35 vs Pb97.5Ag1.5Sn1: properties

Pb65Sn35Pb97.5Ag1.5Sn1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

26 GPa3.8 Msi
16.5 GPa2.4 Msi

Shear Modulus

9.5 GPa1.4 Msi
5.9 GPa0.86 Msi

Bulk Modulus

43 GPa6.2 Msi
42 GPa6.1 Msi

Poisson's Ratio

0.4
0.42

Tensile Strength (Ultimate)

33 MPa4.8 ksi
25 MPa3.6 ksi

Yield Strength (0.2% offset)

21 MPa3 ksi
15 MPa2.2 ksi

Elongation at Break

55%
40%

Shear Strength

26 MPa3.8 ksi
19 MPa2.8 ksi

Fatigue Strength (Endurance Limit)

11 MPa1.6 ksi
8 MPa1.2 ksi

Hardness, Brinell

12 HB
10 HB

Physical

Density and transition temperatures.

Density

9.5 g/cm³0.34 lb/in³
11.28 g/cm³0.41 lb/in³

Melting Point (Solidus)

183°C361 °F
309°C588 °F

Liquidus Temperature

247°C477 °F
309°C588 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
33 W/m·K19.1 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

25 µm/m·K13.9 µin/in·°F
29 µm/m·K16.1 µin/in·°F

Latent Heat of Fusion

38 J/g16.3 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

9.5 % IACS
7.5 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 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)

-0.5 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

Formability (cold)

90 / 100
92 / 100

Castability

85 / 100
88 / 100

Brazeability / Solderability

88 / 100
85 / 100

Polishability

30 / 100
20 / 100

Same in both: Weldability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

128 MJ/kg55,030 BTU/lb
45 MJ/kg19,347 BTU/lb

Embodied Carbon (primary production)

6.7 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

300 L/kg35.9 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)

3 kN·m/kg
2 kN·m/kg

Specific Stiffness (E / density)

2.7 MN·m/kg
1.5 MN·m/kg

Modulus of Resilience

8 kJ/m³
7 kJ/m³

Thermal Diffusivity

28.4 mm²/s
22.5 mm²/s

Same in both: Thermal Shock Resistance Index 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 scalePb65Sn35Pb97.5Ag1.5Sn1

Manufacturing and finishing

CapabilityPb65Sn35Pb97.5Ag1.5Sn1
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Pb65Sn35 vs Pb97.5Ag1.5Sn1 — frequently asked

Is Pb65Sn35 stronger than Pb97.5Ag1.5Sn1?

Yes. Pb65Sn35 has a typical yield strength of 21 MPa (3.05 ksi) against 15 MPa (2.18 ksi) for Pb97.5Ag1.5Sn1 — about 40% more. Tensile strength is 33 MPa (4.79 ksi) vs 25 MPa (3.63 ksi).

Which is cheaper, Pb65Sn35 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, Pb65Sn35 or Pb97.5Ag1.5Sn1?

Pb65Sn35, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for Pb97.5Ag1.5Sn1.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Pb65Sn35 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.