Solder & Low-Melting Alloy Sn50Pb32Cd18
Sn50Pb32Cd18 is a low-melting cadmium-bearing tin-lead solder melting at about 145 °C, developed for joining heat-sensitive assemblies.
Reference datasheet — Sn50Pb32Cd18 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
What is Sn50Pb32Cd18?
Sn50Pb32Cd18 is a low-melting cadmium-bearing tin-lead solder melting at about 145 °C, developed for joining heat-sensitive assemblies. It was supplied as bar, solid and cored wire, foil, preforms and paste, with as-soldered values of 45 MPa tensile, 25 MPa yield, 35 % elongation and 14 HB, and a service ceiling of only 70 °C. The grade is largely obsolete because of cadmium toxicity and regulatory restrictions, and both cadmium and lead fume require controlled ventilation. Bismuth-bearing low-melting solders are the current alternative where a sub-150 °C liquidus is needed. Sn50Pb32Cd18 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 52% of solder & low-melting alloy grades. It melts at 145°C (293 °F). Sn50Pb32Cd18 has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 28 GPa (4.06 Msi).
What is Sn50Pb32Cd18 used for?
- Legacy low-temperature soldering
- Heat-sensitive assembly joining (historic)
- Step soldering beside higher-melting joints
- Repair of obsolete equipment
- Coil and sensor terminations (historic)
- Fusible and thermally limited assemblies (historic)
Limitations
- Needs corrosion protection — 35/100, worse than 94% of solder & low-melting alloy grades
- Limited service temperature — 70°C (158 °F), worse than 91% of solder & low-melting alloy grades
Sn50Pb32Cd18 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn50Pb32Cd18 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 52% of solder & low-melting alloy grades. It melts at 145°C (293 °F).
Mechanical10
Sn50Pb32Cd18 has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 28 GPa (4.06 Msi).
Thermal6
Sn50Pb32Cd18 is rated for continuous service to 70°C (158 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 50% of solder & low-melting alloy grades. Thermal expansion is 27 µm/m·K (15 µin/in·°F).
Electrical3
Sn50Pb32Cd18 conducts electricity at 10 % IACS, better than 54% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), worse than 94% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Sn50Pb32Cd18 takes about 180 MJ of energy and emits 9.8 kg of CO₂ — less than 53% of solder & low-melting alloy grades. Typical recycled content is 25%.
Manufacturability7
Sn50Pb32Cd18's machinability is poor (30/100, worse than 60% of solder & low-melting alloy grades); weldability poor (20/100); formability excellent (90/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. Sn50Pb32Cd18 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn50Pb32Cd18
Is Sn50Pb32Cd18 easy to machine?
Extremely soft and gummy — use sharp high-rake tools, kerosene/light oil lubrication, and capture all chips/dust because cadmium swarf is a health hazard.
Can Sn50Pb32Cd18 be welded?
Not weldable in the usual sense; joints are made by soldering below ~250 °C — keep pot temperature low and ventilated to limit cadmium and lead fume.
Can Sn50Pb32Cd18 be formed, bent or molded?
Casts, extrudes and rolls easily at room temperature into bar, wire, foil and preforms; recrystallises immediately so no annealing is needed.
Sn50Pb32Cd18 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SnISO 9453 alloy 151 | 49 – 51 | 50 |
| Cdrestricted substance (RoHS/REACH Annex XVII) | 17 – 19 | 18 |
| Sbimpurity limit | ≤ 0.1 | |
| Cuimpurity limit | ≤ 0.05 | |
| Biimpurity limit | ≤ 0.1 | |
| Znimpurity limit | ≤ 0 | |
| Alimpurity limit | ≤ 0 | |
| Feimpurity limit | ≤ 0.02 | |
| Asimpurity limit | ≤ 0.03 | |
| Pb | balance |
What surface finishes work on Sn50Pb32Cd18?
Solder joints are normally left as-reflowed after flux-residue cleaning; can be lightly burnished but not anodized or plated, and no protective coating should be assumed to contain the cadmium.
How much does Sn50Pb32Cd18 cost?
Sn50Pb32Cd18 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sn50Pb32Cd18 — frequently asked
What is Sn50Pb32Cd18 used for?
Sn50Pb32Cd18 is typically used for legacy low-temperature soldering, heat-sensitive assembly joining (historic), step soldering beside higher-melting joints, repair of obsolete equipment, coil and sensor terminations (historic) and fusible and thermally limited assemblies (historic). In short: lowest-melting leaded solder; cadmium-bearing, largely obsolete; about 145 °C melt.
What is the yield strength of Sn50Pb32Cd18?
Sn50Pb32Cd18 has a typical yield strength of 25 MPa (3.63 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 61% of solder & low-melting alloy grades.
Is Sn50Pb32Cd18 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 60% of solder & low-melting alloy grades). Extremely soft and gummy — use sharp high-rake tools, kerosene/light oil lubrication, and capture all chips/dust because cadmium swarf is a health hazard.
Can Sn50Pb32Cd18 be welded?
Not readily — weldability is rated poor (20/100). Not weldable in the usual sense; joints are made by soldering below ~250 °C — keep pot temperature low and ventilated to limit cadmium and lead fume.
What surface finishes work on Sn50Pb32Cd18?
Solder joints are normally left as-reflowed after flux-residue cleaning; can be lightly burnished but not anodized or plated, and no protective coating should be assumed to contain the cadmium.
Can Sn50Pb32Cd18 be formed, bent or molded?
Casts, extrudes and rolls easily at room temperature into bar, wire, foil and preforms; recrystallises immediately so no annealing is needed.
What is the maximum service temperature of Sn50Pb32Cd18?
Sn50Pb32Cd18 is rated for continuous use to about 70°C (158 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Sn50Pb32Cd18 cost?
Sn50Pb32Cd18 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ISO 9453 Soft solder alloys — Chemical compositions and forms (alloy 151) — ISO (2020)
- ASM Handbook Vol.3: Alloy Phase Diagrams (Sn-Pb-Cd ternary) — ASM International (1992)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (solders) — ASM International (1990)
- GB/T 3131 (2020)
- REACH Regulation (EC) 1907/2006 Annex XVII, entry 23 (cadmium) — European Commission (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.