Solder & Low-Melting Alloy Sn63Pb37Sb vs Sn97Cu3
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Sn63Pb37Sb and Sn97Cu3 are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: yield strength 38 MPa (5.51 ksi) against 25 MPa (3.63 ksi) for Sn97Cu3, about 52% more; tensile strength follows at 58 MPa (8.41 ksi) vs 35 MPa (5.08 ksi). Sn63Pb37Sb is harder — 16 HB against 15 HB for Sn97Cu3 — which matters for wear surfaces and threads. Sn97Cu3 is lighter (7.33 g/cm³ vs 8.4 g/cm³ for Sn63Pb37Sb) and Sn97Cu3 is stiffer (45 GPa vs 32 GPa). On the shop floor, Sn97Cu3 machines more easily (30 vs 20 out of 100).
Sn63Pb37SbChoose it when strength drives the design, or when surface hardness matters.
Sn97Cu3Choose it when weight is the constraint, or when the part sees heat.
Sn63Pb37Sb vs Sn97Cu3: 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
Hardness, Brinell
Same in both: Fatigue Strength (Endurance Limit) 15 MPa2.2 ksi
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)
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).
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
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
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 | Sn97Cu3 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Sn63Pb37Sb vs Sn97Cu3 — frequently asked
Is Sn63Pb37Sb stronger than Sn97Cu3?
Yes. Sn63Pb37Sb has a typical yield strength of 38 MPa (5.51 ksi) against 25 MPa (3.63 ksi) for Sn97Cu3 — about 52% more. Tensile strength is 58 MPa (8.41 ksi) vs 35 MPa (5.08 ksi).
Which is cheaper, Sn63Pb37Sb or Sn97Cu3?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Sn63Pb37Sb or Sn97Cu3?
Sn97Cu3, 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 Sn63Pb37Sb and Sn97Cu3 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.