Solder & Low-Melting Alloy Sn95.8Ag3.5Cu0.7 REFLOWED
Heat-treated state
ISO 712 · also IEC A38C07
Use these values for joint-level modelling: fast-cooled small solder volumes are stronger and less ductile than bulk cast bar, and creep-soften above ~100 °C.
Values for the REFLOWED condition
What is Sn95.8Ag3.5Cu0.7 REFLOWED?
Sn95.8Ag3.5Cu0.7 REFLOWED is Sn95.8Ag3.5Cu0.7 heat treated to REFLOWED — use these values for joint-level modelling: fast-cooled small solder volumes are stronger and less ductile than bulk cast bar, and creep-soften above ~100 °C. Sn95.8Ag3.5Cu0.7 REFLOWED has a yield strength of 42 MPa (6.09 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 91% of solder & low-melting alloy grades. Elongation at break is 22% and the elastic modulus is 50 GPa (7.25 Msi). Sn95.8Ag3.5Cu0.7 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 217°C (423 °F).
Advantages
- High strength — 42 MPa (6.09 ksi), better than 91% of solder & low-melting alloy grades
- High electrical conductivity — 13 % IACS, better than 87% of solder & low-melting alloy grades
- Stiff — 50 GPa (7.25 Msi), better than 86% of solder & low-melting alloy grades
- Conducts heat well — 58 W/m·K (33.5 BTU/hr·ft·°F), better than 85% of solder & low-melting alloy grades
- Readily welded — 30/100, better than 83% of solder & low-melting alloy grades
Limitations
- Difficult to machine — 20/100, worse than 94% of solder & low-melting alloy grades
- High embodied carbon — 19 kg CO₂/kg, worse than 83% of solder & low-melting alloy grades
- Limited ductility — 22%, worse than 81% of solder & low-melting alloy grades
Sn95.8Ag3.5Cu0.7 REFLOWED properties
Typical room-temperature values for Sn95.8Ag3.5Cu0.7 REFLOWED; 7 are specific to this condition. Other listed values are Sn95.8Ag3.5Cu0.7 reference data and may not represent this condition. Bars are the position among solder & low-melting alloy grades.
Physical3
Sn95.8Ag3.5Cu0.7 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 217°C (423 °F).
Mechanical11
Sn95.8Ag3.5Cu0.7 REFLOWED has a yield strength of 42 MPa (6.09 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 91% of solder & low-melting alloy grades. Elongation at break is 22% and the elastic modulus is 50 GPa (7.25 Msi).
Thermal6
Sn95.8Ag3.5Cu0.7 REFLOWED is rated for continuous service to 125°C (257 °F). It conducts heat at 58 W/m·K (33.5 BTU/hr·ft·°F), better than 85% of solder & low-melting alloy grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
Sn95.8Ag3.5Cu0.7 REFLOWED conducts electricity at 13 % IACS, better than 87% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 82% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Sn95.8Ag3.5Cu0.7 REFLOWED takes about 360 MJ of energy and emits 19 kg of CO₂ — more than 94% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability7
Sn95.8Ag3.5Cu0.7 REFLOWED's machinability is poor (20/100, worse than 94% of solder & low-melting alloy grades); weldability poor (30/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Sn95.8Ag3.5Cu0.7 REFLOWED
Is Sn95.8Ag3.5Cu0.7 easy to machine?
Very soft and gummy — machine only with sharp positive-rake tools, high speed and low feed if trimming preforms; deburring by shearing is preferred.
Can Sn95.8Ag3.5Cu0.7 be welded?
Not fusion-welded; it is a filler alloy — reflow/wave at 235–260 °C peak with no-clean or rosin flux, and keep pot iron/copper contamination in check.
Can Sn95.8Ag3.5Cu0.7 be formed, bent or molded?
Readily cast, extruded, rolled and stamped near room temperature into bar, wire, ribbon and preforms; atomized under inert gas for paste powder.
What surface finishes work on Sn95.8Ag3.5Cu0.7?
No coating needed on the alloy itself; joints are cleaned of flux residue (or left no-clean), and conformal coating is used to suppress electrochemical migration and whisker/oxide issues.
Sn95.8Ag3.5Cu0.7 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 |
|---|---|---|
| Ag | 3.3 – 3.7 | 3.5 |
| Cu | 0.6 – 0.8 | 0.7 |
| PbRoHS lead-free limit; ≤0.1 % in some specs | ≤ 0.07 | |
| Sbimpurity limit | ≤ 0.1 | |
| Biimpurity limit | ≤ 0.1 | |
| Feimpurity limit | ≤ 0.02 | |
| Asimpurity limit | ≤ 0.03 | |
| Cdimpurity limit | ≤ 0 | |
| Znimpurity limit | ≤ 0 | |
| Alimpurity limit | ≤ 0 | |
| Niimpurity limit unless deliberately doped | ≤ 0.01 | |
| Snbalance, ≥95.5 % typical | balance |
Sn95.8Ag3.5Cu0.7 REFLOWED — frequently asked
What is Sn95.8Ag3.5Cu0.7 REFLOWED used for?
Sn95.8Ag3.5Cu0.7 REFLOWED is typically used for SMT reflow soldering, wave soldering and PCB assembly. In short: between SAC305 and SAC387; standard lead-free electronics filler; widest range of product forms.
What is the yield strength of Sn95.8Ag3.5Cu0.7 REFLOWED?
Sn95.8Ag3.5Cu0.7 REFLOWED has a typical yield strength of 42 MPa (6.09 ksi) and a tensile strength of 62 MPa (8.99 ksi) — stronger than 91% of solder & low-melting alloy grades.
Is Sn95.8Ag3.5Cu0.7 REFLOWED easy to machine?
Not especially — machinability is rated poor (20/100, worse than 94% of solder & low-melting alloy grades). Very soft and gummy — machine only with sharp positive-rake tools, high speed and low feed if trimming preforms; deburring by shearing is preferred.
Can Sn95.8Ag3.5Cu0.7 REFLOWED be welded?
Not readily — weldability is rated poor (30/100). Not fusion-welded; it is a filler alloy — reflow/wave at 235–260 °C peak with no-clean or rosin flux, and keep pot iron/copper contamination in check.
What surface finishes work on Sn95.8Ag3.5Cu0.7 REFLOWED?
No coating needed on the alloy itself; joints are cleaned of flux residue (or left no-clean), and conformal coating is used to suppress electrochemical migration and whisker/oxide issues.
Can Sn95.8Ag3.5Cu0.7 REFLOWED be formed, bent or molded?
Readily cast, extruded, rolled and stamped near room temperature into bar, wire, ribbon and preforms; atomized under inert gas for paste powder.
What is the maximum service temperature of Sn95.8Ag3.5Cu0.7 REFLOWED?
Sn95.8Ag3.5Cu0.7 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
- IEC 61190-1-3 Requirements for electronic grade solder alloys — IEC (2007)
- J-STD-006 Requirements for Electronic Grade Solder Alloys and Fluxed/Non-Fluxed Solid Solders — IPC (2013)
- J-STD-005 Requirements for Soldering Pastes — IPC (2012)
- Properties of Lead-Free Solders (solder alloy property database) — NIST (2002)
- ASM Handbook Vol. 3 — Alloy Phase Diagrams (Sn-Ag-Cu) — ASM International (2016)
- SAC lead-free solder alloy data sheets — Indium Corporation / AIM / Kester (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.