Solder & Low-Melting Alloy Sn50Pb49Cu1
Sn50Pb49Cu1 is a lower-tin tin-lead solder microalloyed with about 1 % copper, supplied as ingot, bar, wire, cored wire and ribbon.
Reference datasheet — Sn50Pb49Cu1 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 Sn50Pb49Cu1?
Sn50Pb49Cu1 is a lower-tin tin-lead solder microalloyed with about 1 % copper, supplied as ingot, bar, wire, cored wire and ribbon. It is used mainly as wave-solder bath makeup, where the copper addition limits copper dissolution from pads, boards and carriers while the reduced tin content holds material cost down. Mechanical values are low — 45 MPa tensile strength, 45 % elongation, 14 HB — and the wide 183–216 °C pasty range means joints must be left undisturbed while freezing. The lead content requires RoHS assessment; Sn99.3Cu0.7 is the usual lead-free replacement. Sn50Pb49Cu1 has a density of 8.85 g/cm³ (0.32 lb/in³), heavier than 55% of solder & low-melting alloy grades. It melts at 183°C (361 °F). Sn50Pb49Cu1 has a yield strength of 26 MPa (3.77 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 55% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 30 GPa (4.35 Msi).
What is Sn50Pb49Cu1 used for?
- Wave-solder bath makeup alloy
- Solder bar for pot replenishment
- General electrical joining
- Cored wire for hand soldering of leaded assemblies
- Tinning of copper wire and terminals
- Ribbon and preform stock for tab joints
Advantages
- Ductile — tolerates forming and impact — 45%, better than 84% of solder & low-melting alloy grades
Sn50Pb49Cu1 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn50Pb49Cu1 has a density of 8.85 g/cm³ (0.32 lb/in³), heavier than 55% of solder & low-melting alloy grades. It melts at 183°C (361 °F).
Mechanical10
Sn50Pb49Cu1 has a yield strength of 26 MPa (3.77 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 55% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 30 GPa (4.35 Msi).
Thermal6
Sn50Pb49Cu1 is rated for continuous service to 100°C (212 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 63% of solder & low-melting alloy grades. Thermal expansion is 24.5 µm/m·K (13.6 µin/in·°F).
Electrical3
Sn50Pb49Cu1 conducts electricity at 10.9 % IACS, better than 63% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Sn50Pb49Cu1 takes about 140 MJ of energy and emits 10 kg of CO₂ — less than 61% of solder & low-melting alloy grades. Typical recycled content is 45%.
Manufacturability5
Sn50Pb49Cu1's machinability is poor (25/100, worse than 82% of solder & low-melting alloy grades); 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. Sn50Pb49Cu1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn50Pb49Cu1
Is Sn50Pb49Cu1 easy to machine?
Rarely machined; the alloy is gummy and smears — use sharp positive-rake tools, high rake, low speed and generous lubricant, or shear/stamp instead.
Can Sn50Pb49Cu1 be welded?
Not welded; it IS the filler metal — pot temperature typically 240–270 °C with rosin or organic-acid flux, and the 1 % Cu limits copper dissolution from pads and fixtures.
Can Sn50Pb49Cu1 be formed, bent or molded?
Casts into bars readily and extrudes/rolls cold into wire, ribbon and preforms; the wide 183–216 °C pasty range demands still cooling to avoid hot tears and joint disturbance.
Sn50Pb49Cu1 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 |
|---|---|---|
| Sn | 49.5 – 50.5 | 50 |
| CuPre-saturation to suppress copper dissolution | 0.8 – 1.2 | 1 |
| SbImpurity limit | ≤ 0.2 | |
| BiImpurity limit | ≤ 0.1 | |
| AgImpurity limit | ≤ 0.1 | |
| FeImpurity limit | ≤ 0.02 | |
| AsImpurity limit | ≤ 0.03 | |
| ZnImpurity limit | ≤ 0 | |
| AlImpurity limit | ≤ 0 | |
| CdImpurity limit | ≤ 0 | |
| NiImpurity limit | ≤ 0.01 | |
| Pb | balance |
What surface finishes work on Sn50Pb49Cu1?
Joints are normally left as-soldered after flux-residue cleaning (IPA or saponifier); do not anodize or paint — lead content requires RoHS assessment and no potable-water or food contact.
How much does Sn50Pb49Cu1 cost?
Sn50Pb49Cu1 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.
Sn50Pb49Cu1 — frequently asked
What is Sn50Pb49Cu1 used for?
Sn50Pb49Cu1 is typically used for wave-solder bath makeup alloy, solder bar for pot replenishment, general electrical joining, cored wire for hand soldering of leaded assemblies, tinning of copper wire and terminals and ribbon and preform stock for tab joints. In short: copper-doped wave-bath alloy; lowest-cost tin-lead solder; reduced copper leaching.
What is the yield strength of Sn50Pb49Cu1?
Sn50Pb49Cu1 has a typical yield strength of 26 MPa (3.77 ksi) and a tensile strength of 45 MPa (6.53 ksi) — weaker than 55% of solder & low-melting alloy grades.
Is Sn50Pb49Cu1 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 82% of solder & low-melting alloy grades). Rarely machined; the alloy is gummy and smears — use sharp positive-rake tools, high rake, low speed and generous lubricant, or shear/stamp instead.
Can Sn50Pb49Cu1 be welded?
Not welded; it IS the filler metal — pot temperature typically 240–270 °C with rosin or organic-acid flux, and the 1 % Cu limits copper dissolution from pads and fixtures.
What surface finishes work on Sn50Pb49Cu1?
Joints are normally left as-soldered after flux-residue cleaning (IPA or saponifier); do not anodize or paint — lead content requires RoHS assessment and no potable-water or food contact.
Can Sn50Pb49Cu1 be formed, bent or molded?
Casts into bars readily and extrudes/rolls cold into wire, ribbon and preforms; the wide 183–216 °C pasty range demands still cooling to avoid hot tears and joint disturbance.
What is the maximum service temperature of Sn50Pb49Cu1?
Sn50Pb49Cu1 is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Sn50Pb49Cu1 cost?
Sn50Pb49Cu1 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 — ISO (2020)
- ASTM B32 Standard Specification for Solder Metal — ASTM (2020)
- GB/T 3131 (2020)
- ASM Handbook Vol.3 Alloy Phase Diagrams / Vol.6 Welding, Brazing and Soldering — ASM International (1993)
- Solder bar and wire alloy datasheets (Sn-Pb-Cu grades) — Solder producers (AIM, Nihon Superior, ) (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.