Solder & Low-Melting Alloy Sn96Ag2.5Bi1Cu0.5
ISO 721
Sn96Ag2.5Bi1Cu0.5 is a quaternary tin-silver-bismuth-copper lead-free solder in which the bismuth addition slightly lowers the melting range and improves wetting compared with plain SAC alloys.
Reference datasheet — Sn96Ag2.5Bi1Cu0.5 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.
Sn96Ag2.5Bi1Cu0.5 tempers and conditions
Sn96Ag2.5Bi1Cu0.5 is supplied in one standard condition, AS-REFLOWED.
Supply forms, finishes and certifications
Ways Sn96Ag2.5Bi1Cu0.5 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
BARDefault | Cast bar / ingot for wave and dip soldering | Supply form |
PREFORM | Stamped washers, discs, rings, fluxed or flux-free | Supply form |
SPHERE | BGA/CSP solder spheres | Supply form |
WIRE | Solid drawn wire / ribbon | Supply form |
WIRE-FC | Flux-cored wire | Supply form |
PASTE | Type 3/4/5 powder in no-clean flux vehicle | Printing process |
What is Sn96Ag2.5Bi1Cu0.5?
Sn96Ag2.5Bi1Cu0.5 is a quaternary tin-silver-bismuth-copper lead-free solder in which the bismuth addition slightly lowers the melting range and improves wetting compared with plain SAC alloys. It is the strongest of the SAC-type alloys in this group — 38 MPa yield, 50 MPa tensile, 32% elongation — and is supplied as bar, solid and flux-cored wire, paste, spheres, preforms and as-reflowed joints. Service temperature is limited to 125 °C, and the bismuth content makes it incompatible with tin-lead finishes, where low-melting Sn-Pb-Bi phases and fillet lifting can occur. Plain SAC305 is the alternative on mixed-finish boards. Sn96Ag2.5Bi1Cu0.5 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). Sn96Ag2.5Bi1Cu0.5 has a yield strength of 40 MPa (5.8 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 88% of solder & low-melting alloy grades. Elongation at break is 30% and the elastic modulus is 48 GPa (6.96 Msi).
What is Sn96Ag2.5Bi1Cu0.5 used for?
- Low-temperature reflow soldering
- Mixed-alloy assembly
- Electronics soldering
Advantages
- High strength — 40 MPa (5.8 ksi), better than 88% 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
Sn96Ag2.5Bi1Cu0.5 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn96Ag2.5Bi1Cu0.5 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 has a yield strength of 40 MPa (5.8 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 88% of solder & low-melting alloy grades. Elongation at break is 30% and the elastic modulus is 48 GPa (6.96 Msi).
Thermal6
Sn96Ag2.5Bi1Cu0.5 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 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 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'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. Sn96Ag2.5Bi1Cu0.5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn96Ag2.5Bi1Cu0.5
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.
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 |
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.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Sn96Ag2.5Bi1Cu0.5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- 721
How much does Sn96Ag2.5Bi1Cu0.5 cost?
Sn96Ag2.5Bi1Cu0.5 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.
Sn96Ag2.5Bi1Cu0.5 — frequently asked
What is Sn96Ag2.5Bi1Cu0.5 used for?
Sn96Ag2.5Bi1Cu0.5 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?
Sn96Ag2.5Bi1Cu0.5 has a typical yield strength of 40 MPa (5.8 ksi) and a tensile strength of 52 MPa (7.54 ksi) — stronger than 88% of solder & low-melting alloy grades.
Is Sn96Ag2.5Bi1Cu0.5 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 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?
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 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?
Sn96Ag2.5Bi1Cu0.5 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.
How much does Sn96Ag2.5Bi1Cu0.5 cost?
Sn96Ag2.5Bi1Cu0.5 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
- 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; 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.