Solder & Low-Melting Alloy Pb50Sn50Sb vs Pb65Sn35
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Pb50Sn50Sb and Pb65Sn35 are both solder & low-melting alloy grades. Pb50Sn50Sb is the stronger of the two: yield strength 36 MPa (5.22 ksi) against 21 MPa (3.05 ksi) for Pb65Sn35, about 71% more; tensile strength follows at 48 MPa (6.96 ksi) vs 33 MPa (4.79 ksi). In exchange, Pb65Sn35 is the more ductile: elongation 55% versus 35% for Pb50Sn50Sb, and Pb50Sn50Sb is harder (15 HB vs 12 HB). Pb50Sn50Sb is lighter (8.87 g/cm³ vs 9.5 g/cm³ for Pb65Sn35) and Pb50Sn50Sb is stiffer (30 GPa vs 26 GPa). On the shop floor, Pb65Sn35 welds better (poor vs not recommended).
Pb50Sn50SbChoose it when strength drives the design, or when weight is the constraint.
Pb65Sn35Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
Pb50Sn50Sb vs Pb65Sn35: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
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
Same in both: 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).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Castability
Brazeability / Solderability
Same in both: Formability (cold) 90 / 100 · Polishability 30 / 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 | Pb50Sn50Sb | Pb65Sn35 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Pb50Sn50Sb vs Pb65Sn35 — frequently asked
Is Pb50Sn50Sb stronger than Pb65Sn35?
Yes. Pb50Sn50Sb has a typical yield strength of 36 MPa (5.22 ksi) against 21 MPa (3.05 ksi) for Pb65Sn35 — about 71% more. Tensile strength is 48 MPa (6.96 ksi) vs 33 MPa (4.79 ksi).
Which is cheaper, Pb50Sn50Sb or Pb65Sn35?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Pb50Sn50Sb or Pb65Sn35?
Pb65Sn35, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for Pb50Sn50Sb; for welding the order is Pb65Sn35 first (poor, 20/100) then Pb50Sn50Sb (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Pb50Sn50Sb and Pb65Sn35 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.