Solder & Low-Melting Alloy Pb60Sn40 vs Pb78Sn20Sb2
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Pb60Sn40 and Pb78Sn20Sb2 are both solder & low-melting alloy grades. Pb60Sn40 is the stronger of the two: yield strength 24 MPa (3.48 ksi) against 20 MPa (2.9 ksi) for Pb78Sn20Sb2, about 20% more; tensile strength follows at 38 MPa (5.51 ksi) vs 31 MPa (4.5 ksi). In exchange, Pb78Sn20Sb2 is the more ductile: elongation 45% versus 40% for Pb60Sn40. Pb60Sn40 is lighter (9.29 g/cm³ vs 10.1 g/cm³ for Pb78Sn20Sb2) and Pb78Sn20Sb2 runs hotter in service (110°C vs 100°C continuous). On the shop floor, Pb78Sn20Sb2 machines more easily (fair vs poor).
Pb60Sn40Choose it when strength drives the design, or when weight is the constraint.
Pb78Sn20Sb2Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Pb60Sn40 vs Pb78Sn20Sb2: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all solder & low-melting alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all solder & low-melting alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Same in both: Shear Modulus 9 GPa1.3 Msi · Poisson's Ratio 0.4 · Fatigue Strength (Endurance Limit) 12 MPa1.7 ksi · Hardness, Brinell 12 HB
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Same in both: Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Weldability 20 / 100 · Castability 90 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | Pb60Sn40 | Pb78Sn20Sb2 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Pb60Sn40 vs Pb78Sn20Sb2 — frequently asked
Is Pb60Sn40 stronger than Pb78Sn20Sb2?
Yes. Pb60Sn40 has a typical yield strength of 24 MPa (3.48 ksi) against 20 MPa (2.9 ksi) for Pb78Sn20Sb2 — about 20% more. Tensile strength is 38 MPa (5.51 ksi) vs 31 MPa (4.5 ksi).
Which is cheaper, Pb60Sn40 or Pb78Sn20Sb2?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Pb60Sn40 or Pb78Sn20Sb2?
Pb78Sn20Sb2. Its machinability rates fair (40/100) against poor (30/100) for Pb60Sn40.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Pb60Sn40 and Pb78Sn20Sb2 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.