Solder & Low-Melting Alloy SAC387 vs Sn63Pb37Sb
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy SAC387 and Sn63Pb37Sb are both solder & low-melting alloy grades. Sn63Pb37Sb is the stronger of the two: tensile strength 58 MPa (8.41 ksi) against 50 MPa (7.25 ksi) for SAC387, about 16% more. Sn63Pb37Sb is harder — 16 HB against 15 HB for SAC387 — which matters for wear surfaces and threads. SAC387 is lighter (7.44 g/cm³ vs 8.4 g/cm³ for Sn63Pb37Sb) and SAC387 is stiffer (50 GPa vs 32 GPa). On the shop floor, SAC387 welds better (30 vs 20 out of 100).
SAC387Choose it when weight is the constraint, or when the part sees heat.
Sn63Pb37SbChoose it when strength drives the design, or when surface hardness matters.
SAC387 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
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Same in both: Yield Strength (0.2% offset) 38 MPa5.5 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.
Weldability
Castability
Brazeability / Solderability
Same in both: Machinability 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 Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Strength (UTS / density) 7 kN·m/kg
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 | SAC387 | Sn63Pb37Sb |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
SAC387 vs Sn63Pb37Sb — frequently asked
Is Sn63Pb37Sb stronger than SAC387?
Yes. Sn63Pb37Sb has a typical tensile strength of 58 MPa (8.41 ksi) against 50 MPa (7.25 ksi) for SAC387 — about 16% more.
Which is cheaper, SAC387 or Sn63Pb37Sb?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, SAC387 or Sn63Pb37Sb?
SAC387. Its weldability rates poor (30/100) against poor (20/100) for Sn63Pb37Sb.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SAC387 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.