Solder & Low-Melting Alloy Sn20Pb80 vs Sn63Pb37Sb
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Sn20Pb80 and Sn63Pb37Sb are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 16 MPa (2.32 ksi) for Sn20Pb80, about 138% more; tensile strength follows at 58 MPa (8.41 ksi) vs 29 MPa (4.21 ksi). In exchange, Sn20Pb80 is the more ductile: elongation 40% versus 32% for Sn63Pb37Sb, and Sn63Pb37Sb is harder (16 HB vs 11 HB). Sn63Pb37Sb is lighter (8.4 g/cm³ vs 10.2 g/cm³ for Sn20Pb80) and Sn63Pb37Sb is stiffer (32 GPa vs 23 GPa). On the shop floor, Sn20Pb80 machines more easily (30 vs 20 out of 100).
Sn20Pb80Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Sn63Pb37SbChoose it when strength drives the design, or when weight is the constraint.
Sn20Pb80 vs Sn63Pb37Sb: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Poisson's Ratio 0.4
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
Castability
Brazeability / Solderability
Same in both: Weldability 20 / 100 · Formability (cold) 90 / 100 · 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 | Sn63Pb37Sb |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Sn20Pb80 vs Sn63Pb37Sb — frequently asked
Is Sn63Pb37Sb stronger than Sn20Pb80?
Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 16 MPa (2.32 ksi) for Sn20Pb80 — about 138% more. Tensile strength is 58 MPa (8.41 ksi) vs 29 MPa (4.21 ksi).
Which is cheaper, Sn20Pb80 or Sn63Pb37Sb?
Both sit in the same relative cost tier ($$$$, 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 Sn63Pb37Sb?
Sn20Pb80, by a small margin. Both rate poor for machinability — 30/100 against 20/100 for Sn63Pb37Sb.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Sn20Pb80 and Sn63Pb37Sb 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.