Precious Metal BAg-7
GB BAg56CuZnSn
BAg-7 (Ag56CuZnSn) is a cadmium-free silver brazing filler in which a tin addition lowers the melting range and improves wetting compared with plain Ag-Cu-Zn grades.
Reference datasheet — BAg-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.
BAg-7 tempers and conditions
BAg-7 is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BAg-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 |
|---|---|---|
FC-ROD | Flux-coated rod | Supply form |
Powder/Paste | Powder / paste | Supply form |
Strip/Foil | Strip / Foil / Shim | Supply form |
Wire-Ann | Wire / Strip | Supply form |
Wire/RodDefault | Wire / Rod | Supply form |
What is BAg-7?
BAg-7 (Ag56CuZnSn) is a cadmium-free silver brazing filler in which a tin addition lowers the melting range and improves wetting compared with plain Ag-Cu-Zn grades. It is used for refrigeration circuits and electrical component assembly, and is available as wire and rod, annealed wire, strip and foil, flux-coated rod and powder-paste. Deposit properties are about 290 MPa yield, 415 MPa tensile and 25 % elongation, with roughly 22 % IACS conductivity and a service ceiling near 200 °C. Where cost matters more than braze temperature, the lower-silver BAg-5 (Ag45CuZn) is the obvious substitute. BAg-7 has a density of 9.5 g/cm³ (0.343 lb/in³), lighter than 81% of precious metal grades. It melts at 618°C (1,144 °F). BAg-7 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 89% of precious metal grades. Elongation at break is 25% and the elastic modulus is 85 GPa (12.3 Msi).
What is BAg-7 used for?
- refrigeration systems
- electrical contact assembly
- instrument brazing
Advantages
- High strength — 290 MPa (42.1 ksi), better than 89% of precious metal grades
- Easy to machine — 55/100, better than 86% of precious metal grades
- Low embodied carbon — 65 kg CO₂/kg, better than 78% of precious metal grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Hard to polish — 70/100, worse than 76% of precious metal grades
BAg-7 properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
BAg-7 has a density of 9.5 g/cm³ (0.343 lb/in³), lighter than 81% of precious metal grades. It melts at 618°C (1,144 °F).
Mechanical9
BAg-7 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 89% of precious metal grades. Elongation at break is 25% and the elastic modulus is 85 GPa (12.3 Msi).
Thermal6
BAg-7 is rated for continuous service to 200°C (392 °F). It conducts heat at 70 W/m·K (40.4 BTU/hr·ft·°F), worse than 63% of precious metal grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BAg-7 conducts electricity at 22 % IACS, better than 61% of precious metal grades.
Chemical & Environmental2
Corrosion resistance is good (68/100), worse than 74% of precious metal grades.
Sustainability3
Producing a kilogram of BAg-7 takes about 950 MJ of energy and emits 65 kg of CO₂ — less than 77% of precious metal grades. Typical recycled content is 45%.
Manufacturability6
BAg-7's machinability is good (55/100, better than 86% of precious metal grades); weldability poor (30/100); formability very good (80/100).
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 precious metal family
Yield strength against density for every precious metal grade FabDigit runs. BAg-7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAg-7
Is BAg-7 easy to machine?
Rarely machined; the alloy is soft and gummy — use sharp tools, positive rake and light feeds if trimming preforms.
Can BAg-7 be welded?
Not a weldable structural alloy; it is itself a brazing filler — avoid arc processes that vaporize zinc.
Can BAg-7 be formed, bent or molded?
Readily drawn to fine wire and rolled to foil; anneal between heavy reductions before bending rings or shims.
BAg-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 |
|---|---|---|
| AgAWS A5.8 BAg-7 | 55 – 57 | 56 |
| Cu | 21 – 23 | 22 |
| Snlowers melting range, improves wetting | 4.5 – 5.5 | 5 |
| Cdcadmium-free limit | ≤ 0.01 | |
| Other (total)total of unspecified elements | ≤ 0.15 | |
| Znbalance in most specifications | ≥ 15 (balance) |
What surface finishes work on BAg-7?
Brazed joints are silver-bright but tarnish in sulfur atmospheres; remove flux residue with hot water/citric-acid pickle, then polish or plate as needed.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAg-7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GB (China)
- BAg56CuZnSn
- Also called
- AWS BAg-7
- Similar grades
- P07563
How much does BAg-7 cost?
BAg-7 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAg-7 — frequently asked
What is BAg-7 used for?
BAg-7 is typically used for refrigeration systems, electrical contact assembly and instrument brazing. In short: lower-melting cadmium-free filler; tin-bearing, free-wetting; 56 % Ag electrical-grade filler.
What is the yield strength of BAg-7?
BAg-7 has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 89% of precious metal grades.
Is BAg-7 easy to machine?
Reasonably — machinability is rated good (55/100, better than 86% of precious metal grades). Rarely machined; the alloy is soft and gummy — use sharp tools, positive rake and light feeds if trimming preforms.
Can BAg-7 be welded?
Not readily — weldability is rated poor (30/100). Not a weldable structural alloy; it is itself a brazing filler — avoid arc processes that vaporize zinc.
What surface finishes work on BAg-7?
Brazed joints are silver-bright but tarnish in sulfur atmospheres; remove flux residue with hot water/citric-acid pickle, then polish or plate as needed.
Can BAg-7 be formed, bent or molded?
Readily drawn to fine wire and rolled to foil; anneal between heavy reductions before bending rings or shims.
What is the maximum service temperature of BAg-7?
BAg-7 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAg-7 cost?
BAg-7 is a high-cost precious metal ($$$$), 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
- AWS A5.8M/A5.8 Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- GB/T 10046 (2018)
- ASM Handbook Vol. 6 — Welding, Brazing, and Soldering (Brazing Filler Metals) — ASM International (1993)
- Silvaloy / Braze 560 (BAg-7) technical data — Lucas-Milhaupt (Handy & Harman) (2021)
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.