Solder & Low-Melting Alloy Pb49Sn48Bi3 vs Pb65Sn35
Solder & Low-Melting Alloy · grade comparison
Solder & Low-Melting Alloy Pb49Sn48Bi3 and Pb65Sn35 are both solder & low-melting alloy grades. Pb49Sn48Bi3 is the stronger of the two: yield strength 28 MPa (4.06 ksi) against 21 MPa (3.05 ksi) for Pb65Sn35, about 33% more; tensile strength follows at 45 MPa (6.53 ksi) vs 33 MPa (4.79 ksi). In exchange, Pb65Sn35 is the more ductile: elongation 55% versus 40% for Pb49Sn48Bi3, and Pb49Sn48Bi3 is harder (14 HB vs 12 HB). Pb49Sn48Bi3 is lighter (8.9 g/cm³ vs 9.5 g/cm³ for Pb65Sn35) and Pb49Sn48Bi3 is stiffer (30 GPa vs 26 GPa).
Pb49Sn48Bi3Choose it when strength drives the design, or when weight is the constraint.
Pb65Sn35Choose it when the part is bent, formed or impact-loaded.
Pb49Sn48Bi3 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Same in both: Poisson's Ratio 0.4
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
Min Service Temperature
Same in both: Max Service Temperature (continuous) 100°C212 °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
Polishability
Same in both: Weldability 20 / 100 · Formability (cold) 90 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 300 L/kg35.9 gal/lb
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 | Pb49Sn48Bi3 | Pb65Sn35 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Pb49Sn48Bi3 vs Pb65Sn35 — frequently asked
Is Pb49Sn48Bi3 stronger than Pb65Sn35?
Yes. Pb49Sn48Bi3 has a typical yield strength of 28 MPa (4.06 ksi) against 21 MPa (3.05 ksi) for Pb65Sn35 — about 33% more. Tensile strength is 45 MPa (6.53 ksi) vs 33 MPa (4.79 ksi).
Which is cheaper, Pb49Sn48Bi3 or Pb65Sn35?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Pb49Sn48Bi3 or Pb65Sn35?
Pb65Sn35, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for Pb49Sn48Bi3.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Pb49Sn48Bi3 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.