Solder & Low-Melting Alloy Sn95.8Ag3.5Cu0.7
ISO 712 · also IEC A38C07
Sn95.8Ag3.5Cu0.7 (IEC A38C07) is a tin-silver-copper (SAC) solder intermediate between SAC305 and SAC387 in composition, used in electronics soldering where a specific melting and wetting balance is required.
Reference datasheet — Sn95.8Ag3.5Cu0.7 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.
Sn95.8Ag3.5Cu0.7 tempers and conditions
Sn95.8Ag3.5Cu0.7 is supplied in one standard condition, REFLOWED.
Supply forms, finishes and certifications
Ways Sn95.8Ag3.5Cu0.7 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 |
CORED | Flux-cored wire | Supply form |
PASTE-T3 | Solder paste, Type 3 powder (25–45 µm) with no-clean flux | Supply form |
PASTE-T4 | Solder paste, Type 4 powder | Supply form |
PASTE-T5 | Solder paste, Type 5 powder | Supply form |
PREFORM | Stamped washers, discs, rings and pellets | Supply form |
SPHERE | BGA/CSP solder spheres | Supply form |
WIRE | Solid extruded/drawn wire | Supply form |
POWDER | Inert-gas atomized spherical powder | Printing process |
What is Sn95.8Ag3.5Cu0.7?
Sn95.8Ag3.5Cu0.7 (IEC A38C07) is a tin-silver-copper (SAC) solder intermediate between SAC305 and SAC387 in composition, used in electronics soldering where a specific melting and wetting balance is required. It is stocked in the widest range of forms — bar, solid and cored wire, Type 3/4/5 paste, powder, spheres and preforms — for reflow and wave lines running 235–260 °C peak. Bulk properties are 30 MPa yield, 45 MPa tensile, 35% elongation and 14 HB with service to about 125 °C, so it is a filler alloy and not a structural metal. SAC305 is the more widely stocked substitute. Sn95.8Ag3.5Cu0.7 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). Sn95.8Ag3.5Cu0.7 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 45 MPa (6.53 ksi) — stronger than 61% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 50 GPa (7.25 Msi).
What is Sn95.8Ag3.5Cu0.7 used for?
- SMT reflow soldering
- Wave soldering
- PCB assembly
Advantages
- 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
- High service temperature — 125°C (257 °F), better than 80% 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
Sn95.8Ag3.5Cu0.7 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn95.8Ag3.5Cu0.7 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 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 45 MPa (6.53 ksi) — stronger than 61% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 50 GPa (7.25 Msi).
Thermal6
Sn95.8Ag3.5Cu0.7 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 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 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's machinability is poor (20/100, worse than 94% of solder & low-melting alloy grades); weldability poor (30/100); formability excellent (85/100).
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. Sn95.8Ag3.5Cu0.7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn95.8Ag3.5Cu0.7
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.
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 |
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.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Sn95.8Ag3.5Cu0.7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- 712
- Trade names
- IEC A38C07
How much does Sn95.8Ag3.5Cu0.7 cost?
Sn95.8Ag3.5Cu0.7 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sn95.8Ag3.5Cu0.7 — frequently asked
What is Sn95.8Ag3.5Cu0.7 used for?
Sn95.8Ag3.5Cu0.7 is typically used for SMT reflow soldering, wave soldering and PCB assembly. In short: between SAC305 and SAC387; standard lead-free electronics filler; widest range of product forms.
What is the yield strength of Sn95.8Ag3.5Cu0.7?
Sn95.8Ag3.5Cu0.7 has a typical yield strength of 30 MPa (4.35 ksi) and a tensile strength of 45 MPa (6.53 ksi) — stronger than 61% of solder & low-melting alloy grades.
Is Sn95.8Ag3.5Cu0.7 easy to machine?
Not especially — machinability is rated poor (20/100, worse than 94% of solder & low-melting alloy grades). Very soft and gummy — machine only with sharp positive-rake tools, high speed and low feed if trimming preforms; deburring by shearing is preferred.
Can Sn95.8Ag3.5Cu0.7 be welded?
Not readily — weldability is rated poor (30/100). Not fusion-welded; it is a filler alloy — reflow/wave at 235–260 °C peak with no-clean or rosin flux, and keep pot iron/copper contamination in check.
What surface finishes work on Sn95.8Ag3.5Cu0.7?
No coating needed on the alloy itself; joints are cleaned of flux residue (or left no-clean), and conformal coating is used to suppress electrochemical migration and whisker/oxide issues.
Can Sn95.8Ag3.5Cu0.7 be formed, bent or molded?
Readily cast, extruded, rolled and stamped near room temperature into bar, wire, ribbon and preforms; atomized under inert gas for paste powder.
What is the maximum service temperature of Sn95.8Ag3.5Cu0.7?
Sn95.8Ag3.5Cu0.7 is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Sn95.8Ag3.5Cu0.7 cost?
Sn95.8Ag3.5Cu0.7 is a high-cost solder & low-melting alloy ($$$$), 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
- 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; 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.