Solder & Low-Melting Alloy Sn63Pb37Sb vs Sn99.3Cu0.7
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Sn63Pb37Sb and Sn99.3Cu0.7 are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 15 MPa (2.18 ksi) for Sn99.3Cu0.7, about 153% more; tensile strength follows at 58 MPa (8.41 ksi) vs 28 MPa (4.06 ksi). In exchange, Sn99.3Cu0.7 is the more ductile: elongation 40% versus 32% for Sn63Pb37Sb, and Sn63Pb37Sb is harder (16 HB vs 14 HB). Sn99.3Cu0.7 is lighter (7.31 g/cm³ vs 8.4 g/cm³ for Sn63Pb37Sb) and Sn99.3Cu0.7 is stiffer (43 GPa vs 32 GPa).
Sn63Pb37SbChoose it when strength drives the design.
Sn99.3Cu0.7Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
Sn63Pb37Sb vs Sn99.3Cu0.7: 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
Hardness, Vickers
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
Same in both: Max Service Temperature (continuous) 100°C212 °F · Min Service Temperature -55°C-67 °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.
Weldability
Castability
Same in both: Machinability 20 / 100 · Formability (cold) 90 / 100 · Brazeability / Solderability 100 / 100 · Polishability 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
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 | Sn63Pb37Sb | Sn99.3Cu0.7 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Sn63Pb37Sb vs Sn99.3Cu0.7 — frequently asked
Is Sn63Pb37Sb stronger than Sn99.3Cu0.7?
Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 15 MPa (2.18 ksi) for Sn99.3Cu0.7 — about 153% more. Tensile strength is 58 MPa (8.41 ksi) vs 28 MPa (4.06 ksi).
Which is cheaper, Sn63Pb37Sb or Sn99.3Cu0.7?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose Sn63Pb37Sb over Sn99.3Cu0.7?
Pick Sn63Pb37Sb when strength drives the design. Pick Sn99.3Cu0.7 when the part is bent, formed or impact-loaded, or when weight is the constraint.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Sn63Pb37Sb and Sn99.3Cu0.7 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.