Solder & Low-Melting Alloy Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED
Heat-treated state
ISO 721
Use for joint-level design data: fine Ag3Sn/Cu6Sn5 dispersion gives higher strength but lower ductility than cast bar, and strength decays with isothermal ageing at ≥100 °C.
Values for the AS-REFLOWED condition
What is Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED?
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED is Sn96Ag2.5Bi1Cu0.5 heat treated to AS-REFLOWED — use for joint-level design data: fine Ag3Sn/Cu6Sn5 dispersion gives higher strength but lower ductility than cast bar, and strength decays with isothermal ageing at ≥100 °C. Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED has a yield strength of 48 MPa (6.96 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 99% of solder & low-melting alloy grades. Elongation at break is 20% and the elastic modulus is 48 GPa (6.96 Msi). Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED has a density of 7.4 g/cm³ (0.267 lb/in³), lighter than 67% of solder & low-melting alloy grades. It melts at 214°C (417 °F).
Advantages
- High strength — 48 MPa (6.96 ksi), better than 99% of solder & low-melting alloy grades
- High electrical conductivity — 12.5 % IACS, better than 82% of solder & low-melting alloy grades
- Stiff — 48 GPa (6.96 Msi), better than 81% of solder & low-melting alloy grades
- Conducts heat well — 56 W/m·K (32.4 BTU/hr·ft·°F), better than 81% of solder & low-melting alloy grades
- High service temperature — 125°C (257 °F), better than 80% of solder & low-melting alloy grades
Limitations
- High embodied carbon — 22 kg CO₂/kg, worse than 92% of solder & low-melting alloy grades
- Limited ductility — 20%, worse than 82% of solder & low-melting alloy grades
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED properties
Typical room-temperature values for Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED; 6 are specific to this condition. Other listed values are Sn96Ag2.5Bi1Cu0.5 reference data and may not represent this condition. Bars are the position among solder & low-melting alloy grades.
Physical3
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED has a density of 7.4 g/cm³ (0.267 lb/in³), lighter than 67% of solder & low-melting alloy grades. It melts at 214°C (417 °F).
Mechanical10
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED has a yield strength of 48 MPa (6.96 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 99% of solder & low-melting alloy grades. Elongation at break is 20% and the elastic modulus is 48 GPa (6.96 Msi).
Thermal6
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED is rated for continuous service to 125°C (257 °F). It conducts heat at 56 W/m·K (32.4 BTU/hr·ft·°F), better than 81% of solder & low-melting alloy grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED conducts electricity at 12.5 % IACS, better than 82% 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 Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED takes about 350 MJ of energy and emits 22 kg of CO₂ — more than 92% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability5
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED's machinability is poor (25/100, worse than 82% of solder & low-melting alloy grades); formability excellent (90/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED
Is Sn96Ag2.5Bi1Cu0.5 easy to machine?
Rarely machined — very soft and gummy; shear, saw or stamp with sharp tools and wax lubricant rather than turning or milling.
Can Sn96Ag2.5Bi1Cu0.5 be welded?
Not a weldable structural alloy; it IS the filler — join by reflow (peak 235–250 °C), wave (pot 250–265 °C) or iron/laser soldering with matching no-clean flux, and never mix with Sn-Pb finishes to avoid low-melting Sn-Pb-Bi phases and fillet lifting.
Can Sn96Ag2.5Bi1Cu0.5 be formed, bent or molded?
Extrudes and draws easily into wire, ribbon and stamped preforms at room temperature; atomises to Type 3–5 spherical powder for paste.
What surface finishes work on Sn96Ag2.5Bi1Cu0.5?
No plating or anodizing; clean flux residues (or use no-clean profile), avoid abrasive polishing which smears the surface, and store in dry, sulphur-free packaging to limit oxide/tarnish growth.
Sn96Ag2.5Bi1Cu0.5 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 |
|---|---|---|
| Agforms Ag3Sn strengthening precipitates | 2.3 – 2.7 | 2.5 |
| Bilowers solidus and improves wetting/spread | 0.8 – 1.2 | 1 |
| Cusuppresses Cu dissolution from pads, forms Cu6Sn5 | 0.4 – 0.6 | 0.5 |
| PbRoHS limit 0.1 wt % on the homogeneous material; keep low to avoid low-melting Sn-Pb-Bi phase | ≤ 0.05 | |
| Sbimpurity limit | ≤ 0.05 | |
| Feimpurity limit | ≤ 0.02 | |
| Znimpurity limit, degrades wetting | ≤ 0 | |
| Alimpurity limit, causes gritty joints | ≤ 0 | |
| Cdimpurity limit | ≤ 0 | |
| Asimpurity limit | ≤ 0.03 | |
| Snbalance, ≈95.9–96.5 % | balance |
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED — frequently asked
What is Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED used for?
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED is typically used for low-temperature reflow soldering, mixed-alloy assembly and electronics soldering. In short: highest strength SAC variant; bismuth-improved wetting; not for Sn-Pb finishes.
What is the yield strength of Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED?
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED has a typical yield strength of 48 MPa (6.96 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 99% of solder & low-melting alloy grades.
Is Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED easy to machine?
Not especially — machinability is rated poor (25/100, worse than 82% of solder & low-melting alloy grades). Rarely machined — very soft and gummy; shear, saw or stamp with sharp tools and wax lubricant rather than turning or milling.
Can Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED be welded?
Not a weldable structural alloy; it IS the filler — join by reflow (peak 235–250 °C), wave (pot 250–265 °C) or iron/laser soldering with matching no-clean flux, and never mix with Sn-Pb finishes to avoid low-melting Sn-Pb-Bi phases and fillet lifting.
What surface finishes work on Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED?
No plating or anodizing; clean flux residues (or use no-clean profile), avoid abrasive polishing which smears the surface, and store in dry, sulphur-free packaging to limit oxide/tarnish growth.
Can Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED be formed, bent or molded?
Extrudes and draws easily into wire, ribbon and stamped preforms at room temperature; atomises to Type 3–5 spherical powder for paste.
What is the maximum service temperature of Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED?
Sn96Ag2.5Bi1Cu0.5 AS-REFLOWED is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- J-STD-006C — Requirements for Electronic Grade Solder Alloys and Fluxed/Non-Fluxed Solid Solders — IPC/JEDEC (2013)
- ISO 9453 — Soft solder alloys: chemical composition and forms — ISO (2020)
- GB/T 20422 — (Lead-free solder) — SAC (China) (2018)
- Properties of Lead-Free Solders / Solder Alloy Database — NIST (2002)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (soldering section) — ASM International (1993)
- Lead-free Sn-Ag-Bi-Cu solder bar/wire/paste technical data — Indium Corporation / Senju Metal / Nihon Superior (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.