Solder & Low-Melting Alloy Pb80Sn20 vs Pb85Sn15
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Pb80Sn20 and Pb85Sn15 are both solder & low-melting alloy grades. Pb80Sn20 is the stronger of the two: yield strength 14 MPa (2.03 ksi) against 13 MPa (1.89 ksi) for Pb85Sn15, about 8% more; tensile strength follows at 27 MPa (3.92 ksi) vs 25 MPa (3.63 ksi). Pb80Sn20 is harder — 11 HB against 10 HB for Pb85Sn15 — which matters for wear surfaces and threads. On the shop floor, Pb85Sn15 machines more easily (very good vs fair) and Pb85Sn15 forms better (95 vs 85 out of 100).
Pb80Sn20Choose it when strength drives the design, or when surface hardness matters.
Pb85Sn15Choose it when the part is machined in volume.
Pb80Sn20 vs Pb85Sn15: 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.
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Shear Strength
Hardness, Brinell
Fatigue Strength (Endurance Limit)
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 23 GPa3.3 Msi · Shear Modulus 8.2 GPa1.2 Msi · Elongation at Break 40%
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)
Same in both: Latent Heat of Fusion 30 J/g12.9 BTU/lb · Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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)
Castability
Brazeability / Solderability
Polishability
Same in both: Weldability 20 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Same in both: Embodied Carbon (primary production) 4.5 kg CO₂/kg · Typical Recycled Content 60%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Same in both: Modulus of Resilience 4 kJ/m³ · 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.
Manufacturing and finishing
| Capability | Pb80Sn20 | Pb85Sn15 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Pb80Sn20 vs Pb85Sn15 — frequently asked
Is Pb80Sn20 stronger than Pb85Sn15?
Yes. Pb80Sn20 has a typical yield strength of 14 MPa (2.03 ksi) against 13 MPa (1.89 ksi) for Pb85Sn15 — about 8% more. Tensile strength is 27 MPa (3.92 ksi) vs 25 MPa (3.63 ksi).
Which is cheaper, Pb80Sn20 or Pb85Sn15?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Pb80Sn20 or Pb85Sn15?
Pb85Sn15. Its machinability rates very good (75/100) against fair (35/100) for Pb80Sn20.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Pb80Sn20 and Pb85Sn15 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.