Solder & Low-Melting Alloy Sn20Pb80 vs Sn60Pb40Sb
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Sn20Pb80 and Sn60Pb40Sb are both solder & low-melting alloy grades. Sn60Pb40Sb is the stronger of the two: yield strength 32 MPa (4.64 ksi) against 16 MPa (2.32 ksi) for Sn20Pb80, about 100% more; tensile strength follows at 52 MPa (7.54 ksi) vs 29 MPa (4.21 ksi). In exchange, Sn20Pb80 is the more ductile: elongation 40% versus 35% for Sn60Pb40Sb, and Sn60Pb40Sb is harder (15 HB vs 11 HB). Sn60Pb40Sb is lighter (8.5 g/cm³ vs 10.2 g/cm³ for Sn20Pb80) and Sn60Pb40Sb is stiffer (31 GPa vs 23 GPa). On the shop floor, Sn20Pb80 welds better (poor vs not recommended).
Sn20Pb80Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Sn60Pb40SbChoose it when strength drives the design, or when weight is the constraint.
Sn20Pb80 vs Sn60Pb40Sb: 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Charpy V-Notch Impact (RT)
Hardness, Vickers
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 183°C361 °F
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)
Same in both: Min Service Temperature -55°C-67 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Polishability 25 / 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 | Sn20Pb80 | Sn60Pb40Sb |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Sn20Pb80 vs Sn60Pb40Sb — frequently asked
Is Sn60Pb40Sb stronger than Sn20Pb80?
Yes. Sn60Pb40Sb has a typical yield strength of 32 MPa (4.64 ksi) against 16 MPa (2.32 ksi) for Sn20Pb80 — about 100% more. Tensile strength is 52 MPa (7.54 ksi) vs 29 MPa (4.21 ksi).
Which is cheaper, Sn20Pb80 or Sn60Pb40Sb?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Sn20Pb80 or Sn60Pb40Sb?
Sn60Pb40Sb. Its machinability rates fair (35/100) against poor (30/100) for Sn20Pb80; for welding the order is Sn20Pb80 first (poor, 20/100) then Sn60Pb40Sb (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Sn20Pb80 and Sn60Pb40Sb 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.