Solder & Low-Melting Alloy Sn97Ag3
Sn97Ag3 is a reduced-silver binary tin-silver lead-free solder that lowers cost relative to eutectic Sn-Ag at the expense of a slightly wider pasty range, with about 48 MPa tensile, 30 MPa yield, 38% elongation and 15 HB.
Reference datasheet — Sn97Ag3 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 Sn97Ag3?
Sn97Ag3 is a reduced-silver binary tin-silver lead-free solder that lowers cost relative to eutectic Sn-Ag at the expense of a slightly wider pasty range, with about 48 MPa tensile, 30 MPa yield, 38% elongation and 15 HB. It is used for cost-sensitive lead-free electrical and mechanical joining and is available as bar, solid and flux-cored wire, paste, preforms and balls. Maximum service temperature is about 125 °C, and the wider freezing range needs slightly more attention in wave and drag soldering. Sn96.5Ag3.5 is the obvious substitute when a sharp melting point is required. Sn97Ag3 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). Sn97Ag3 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 61% of solder & low-melting alloy grades. Elongation at break is 38% and the elastic modulus is 51 GPa (7.4 Msi).
What is Sn97Ag3 used for?
- Cost-sensitive lead-free soldering
- General electrical and mechanical joining
- Wave and drag soldering of through-hole boards
- Reflow paste for SMT assembly
- Stamped preforms and solder balls
- Flux-cored wire for hand soldering and rework
Advantages
- High electrical conductivity — 14 % IACS, better than 94% of solder & low-melting alloy grades
- Stiff — 51 GPa (7.4 Msi), better than 91% 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 — 20 kg CO₂/kg, worse than 86% 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
Sn97Ag3 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn97Ag3 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
Sn97Ag3 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 61% of solder & low-melting alloy grades. Elongation at break is 38% and the elastic modulus is 51 GPa (7.4 Msi).
Thermal6
Sn97Ag3 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
Sn97Ag3 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 Sn97Ag3 takes about 350 MJ of energy and emits 20 kg of CO₂ — more than 92% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability6
Sn97Ag3'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. Sn97Ag3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn97Ag3
Is Sn97Ag3 easy to machine?
Very soft and prone to sticking to tools; parts are normally sheared, blanked or drawn rather than cut. If cutting is unavoidable, use sharp large-positive-rake tools at low speed.
Can Sn97Ag3 be welded?
Not a structural welding filler — it is the solder itself. Run wave pots at 255–265 °C and reflow peaks at 245–255 °C, using nitrogen or an active flux to obtain good wetting.
Can Sn97Ag3 be formed, bent or molded?
After casting to ingot it can be hot rolled and cold drawn into wire, foil and preform strip. Atomised powder is blended with flux to make solder paste.
Sn97Ag3 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 |
|---|---|---|
| Agnominal composition of ISO 9453 alloy 702 | 2.8 – 3.2 | 3 |
| PbRoHS lead-free limit, usually ≤0.05 | ≤ 0.07 | |
| Cuimpurity | ≤ 0.05 | |
| Sbimpurity | ≤ 0.05 | |
| Biimpurity | ≤ 0.1 | |
| Feimpurity | ≤ 0.02 | |
| Asimpurity | ≤ 0.03 | |
| Znstrictly limited (affects wetting) | ≤ 0 | |
| Alstrictly limited (affects wetting) | ≤ 0 | |
| Cdlimit for hazardous element | ≤ 0 | |
| Niimpurity | ≤ 0.01 | |
| Sn | balance |
What surface finishes work on Sn97Ag3?
Wash rosin or no-clean residues after soldering with IPA or aqueous cleaner; joints can be conformal-coated to resist damp-heat corrosion. Anodizing is not applicable.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Sn97Ag3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- IEC A30
How much does Sn97Ag3 cost?
Sn97Ag3 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.
Sn97Ag3 — frequently asked
What is Sn97Ag3 used for?
Sn97Ag3 is typically used for cost-sensitive lead-free soldering, general electrical and mechanical joining, wave and drag soldering of through-hole boards, reflow paste for SMT assembly, stamped preforms and solder balls and flux-cored wire for hand soldering and rework. In short: lower-silver Sn-Ag solder; cost-reduced eutectic substitute; slightly wider pasty range.
What is the yield strength of Sn97Ag3?
Sn97Ag3 has a typical yield strength of 30 MPa (4.35 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 61% of solder & low-melting alloy grades.
Is Sn97Ag3 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 82% of solder & low-melting alloy grades). Very soft and prone to sticking to tools; parts are normally sheared, blanked or drawn rather than cut. If cutting is unavoidable, use sharp large-positive-rake tools at low speed.
Can Sn97Ag3 be welded?
Not a structural welding filler — it is the solder itself. Run wave pots at 255–265 °C and reflow peaks at 245–255 °C, using nitrogen or an active flux to obtain good wetting.
What surface finishes work on Sn97Ag3?
Wash rosin or no-clean residues after soldering with IPA or aqueous cleaner; joints can be conformal-coated to resist damp-heat corrosion. Anodizing is not applicable.
Can Sn97Ag3 be formed, bent or molded?
After casting to ingot it can be hot rolled and cold drawn into wire, foil and preform strip. Atomised powder is blended with flux to make solder paste.
What is the maximum service temperature of Sn97Ag3?
Sn97Ag3 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 Sn97Ag3 cost?
Sn97Ag3 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 (alloy 702) — ISO (2020)
- J-STD-006 Requirements for Electronic Grade Solder Alloys — IPC (2013)
- GB/T 20422 (2018)
- Properties of Lead-Free Solders (Solder Data Repository) — NIST (2002)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (Soldering section) — ASM International (1993)
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.