Solder & Low-Melting Alloy Sn96.3Ag3.7
Sn96.3Ag3.7 is a near-eutectic binary tin-silver lead-free solder with no copper addition, providing about 50 MPa tensile strength, 35 MPa yield, 40% elongation and good creep resistance at 15 HB.
Reference datasheet — Sn96.3Ag3.7 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.
What is Sn96.3Ag3.7?
Sn96.3Ag3.7 is a near-eutectic binary tin-silver lead-free solder with no copper addition, providing about 50 MPa tensile strength, 35 MPa yield, 40% elongation and good creep resistance at 15 HB. Engineers choose it for electronics and mechanical joints where the cost of copper additions is not warranted, and it is stocked as bar, solid and flux-cored wire, paste, preform, foil and spheres. Service temperature is limited to roughly 125 °C, and silver content keeps the price above Sn-Cu solders. Eutectic Sn96.5Ag3.5 is the closest alternative and melts more sharply. Sn96.3Ag3.7 has a density of 7.37 g/cm³ (0.266 lb/in³), lighter than 78% of solder & low-melting alloy grades. It melts at 221°C (430 °F). Sn96.3Ag3.7 has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 81% of solder & low-melting alloy grades. Elongation at break is 40% and the elastic modulus is 50 GPa (7.25 Msi).
What is Sn96.3Ag3.7 used for?
- lead-free electronics soldering
- solar cell tabbing/ribbon soldering
- general mechanical solder joints
Advantages
- High electrical conductivity — 14 % IACS, better than 94% of solder & low-melting alloy grades
- Stiff — 50 GPa (7.25 Msi), better than 86% of solder & low-melting alloy grades
- High strength — 35 MPa (5.08 ksi), 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
- Lightweight — 7.37 g/cm³ (0.266 lb/in³), better than 78% of solder & low-melting alloy grades
Limitations
- High embodied carbon — 19 kg CO₂/kg, worse than 83% of solder & low-melting alloy grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 76% of solder & low-melting alloy grades
Sn96.3Ag3.7 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn96.3Ag3.7 has a density of 7.37 g/cm³ (0.266 lb/in³), lighter than 78% of solder & low-melting alloy grades. It melts at 221°C (430 °F).
Mechanical11
Sn96.3Ag3.7 has a yield strength of 35 MPa (5.08 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 81% of solder & low-melting alloy grades. Elongation at break is 40% and the elastic modulus is 50 GPa (7.25 Msi).
Thermal6
Sn96.3Ag3.7 is rated for continuous service to 125°C (257 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 76% of solder & low-melting alloy grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
Sn96.3Ag3.7 conducts electricity at 14 % IACS, better than 94% 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 Sn96.3Ag3.7 takes about 265 MJ of energy and emits 19 kg of CO₂ — more than 63% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability7
Sn96.3Ag3.7's machinability is poor (25/100, worse than 82% of solder & low-melting alloy grades); weldability poor (20/100); 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. Sn96.3Ag3.7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn96.3Ag3.7
Is Sn96.3Ag3.7 easy to machine?
Machining is rarely needed and difficult — the alloy smears and loads tools; use sharp high-rake tools, paraffin/kerosene lubrication or shear/stamp instead.
Can Sn96.3Ag3.7 be welded?
Not fusion-welded; joined by soldering at 240–260 °C peak with rosin/no-clean or water-soluble flux, preferably under N₂ to limit dross.
Can Sn96.3Ag3.7 be formed, bent or molded?
Very ductile — extrudes, draws to fine wire and rolls to foil at room temperature; anneals at ambient so no intermediate heat treatment is required.
Sn96.3Ag3.7 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 |
|---|---|---|
| AgAg3Sn strengthening phase | 3.5 – 4 | 3.7 |
| Pbimpurity limit; RoHS lead-free grades typically < 0.05 % | ≤ 0.1 | |
| Cuimpurity limit | ≤ 0.05 | |
| Sbimpurity limit | ≤ 0.05 | |
| Biimpurity limit | ≤ 0.1 | |
| Feimpurity limit | ≤ 0.02 | |
| Asimpurity limit | ≤ 0.03 | |
| Cdimpurity limit | ≤ 0 | |
| Znimpurity limit | ≤ 0 | |
| Alimpurity limit | ≤ 0 | |
| Niimpurity limit | ≤ 0.01 | |
| Snbalance, min ~96.0 % | balance |
What surface finishes work on Sn96.3Ag3.7?
Joints are cleaned of flux residue (IPA or DI water depending on flux class); the solder itself is not plated or anodised, and conformal coating is used where tarnish or whisker growth matters.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Sn96.3Ag3.7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- IEC A37
How much does Sn96.3Ag3.7 cost?
Sn96.3Ag3.7 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sn96.3Ag3.7 — frequently asked
What is Sn96.3Ag3.7 used for?
Sn96.3Ag3.7 is typically used for lead-free electronics soldering, solar cell tabbing/ribbon soldering and general mechanical solder joints. In short: copper-free Sn-Ag solder; good creep resistance; very ductile joints.
What is the yield strength of Sn96.3Ag3.7?
Sn96.3Ag3.7 has a typical yield strength of 35 MPa (5.08 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 81% of solder & low-melting alloy grades.
Is Sn96.3Ag3.7 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 82% of solder & low-melting alloy grades). Machining is rarely needed and difficult — the alloy smears and loads tools; use sharp high-rake tools, paraffin/kerosene lubrication or shear/stamp instead.
Can Sn96.3Ag3.7 be welded?
Not readily — weldability is rated poor (20/100). Not fusion-welded; joined by soldering at 240–260 °C peak with rosin/no-clean or water-soluble flux, preferably under N₂ to limit dross.
What surface finishes work on Sn96.3Ag3.7?
Joints are cleaned of flux residue (IPA or DI water depending on flux class); the solder itself is not plated or anodised, and conformal coating is used where tarnish or whisker growth matters.
Can Sn96.3Ag3.7 be formed, bent or molded?
Very ductile — extrudes, draws to fine wire and rolls to foil at room temperature; anneals at ambient so no intermediate heat treatment is required.
What is the maximum service temperature of Sn96.3Ag3.7?
Sn96.3Ag3.7 is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Sn96.3Ag3.7 cost?
Sn96.3Ag3.7 is a high-cost solder & low-melting alloy ($$$$), 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
- ISO 9453 — Soft solder alloys: chemical compositions and forms — ISO (2020)
- J-STD-006 — Requirements for Electronic Grade Solder Alloys and Fluxed/Non-Fluxed Solid Solders — IPC/JEDEC (2013)
- GB/T 20422 (2018)
- ASM Handbook Vol.3 — Alloy Phase Diagrams (Ag-Sn system) — ASM International (2016)
- NIST Properties of Lead-Free Solders / Solder Database — NIST (2002)
- Lead-free solder alloy datasheets (Sn-Ag / Sn3.5Ag family) — Indium Corporation / AIM Solder / 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.