Precious Metal BAg-8a
UNS P07723
BAg-8a (UNS P07723) is a lithium-bearing modification of the 72Ag-28Cu eutectic that self-fluxes on stainless steel and other oxide-forming metals, so no separate flux is required.
Reference datasheet — BAg-8a 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-8a tempers and conditions
BAg-8a is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BAg-8a is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
POWDER-PASTE | Powder / Paste | Supply form |
PREFORM | Stamped rings, washers and shapes | Supply form |
ROD | Straight lengths, bare | Supply form |
STRIP | Strip / Foil | Supply form |
WIREDefault | Drawn, annealed spool/coil | Supply form |
What is BAg-8a?
BAg-8a (UNS P07723) is a lithium-bearing modification of the 72Ag-28Cu eutectic that self-fluxes on stainless steel and other oxide-forming metals, so no separate flux is required. Engineers use it for furnace and vacuum brazing where flux residue cannot be tolerated; it is supplied as wire, rod, strip, stamped preforms, powder and paste. As-brazed values are about 330 MPa tensile, 22% elongation and 70 HB, with high cold formability. Braze at 771-816 °C with 0.03-0.08 mm clearance; when a zinc-free filler is needed at higher temperature, BVAg-0 is the alternative. BAg-8a has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 766°C (1,411 °F). BAg-8a has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 59% of precious metal grades. Elongation at break is 22% and the elastic modulus is 85 GPa (12.3 Msi).
What is BAg-8a used for?
- stainless steel furnace brazing without flux
- vacuum and controlled-atmosphere brazing
- honeycomb structure joining
Advantages
- High electrical conductivity — 87 % IACS, better than 93% of precious metal grades
- Conducts heat well — 350 W/m·K (202.2 BTU/hr·ft·°F), better than 89% of precious metal grades
Limitations
- Difficult to machine — 30/100, worse than 86% of precious metal grades
- Difficult to weld — 20/100, worse than 86% of precious metal grades
BAg-8a properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
BAg-8a has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 766°C (1,411 °F).
Mechanical10
BAg-8a has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 59% of precious metal grades. Elongation at break is 22% and the elastic modulus is 85 GPa (12.3 Msi).
Thermal6
BAg-8a is rated for continuous service to 370°C (698 °F). It conducts heat at 350 W/m·K (202.2 BTU/hr·ft·°F), better than 89% of precious metal grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BAg-8a conducts electricity at 87 % IACS, better than 93% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), worse than 74% of precious metal grades.
Sustainability4
Producing a kilogram of BAg-8a takes about 1,050 MJ of energy and emits 80 kg of CO₂ — less than 75% of precious metal grades. Typical recycled content is 45%.
Manufacturability7
BAg-8a's machinability is poor (30/100, worse than 86% of precious metal grades); weldability poor (20/100); 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 precious metal family
Yield strength against density for every precious metal grade FabDigit runs. BAg-8a is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAg-8a
Is BAg-8a easy to machine?
Rarely machined; the soft eutectic is gummy — use sharp high-rake tools, light feeds and good lubrication if trimming preforms.
Can BAg-8a be welded?
Not a structural weld metal; it is the filler itself — braze in vacuum (10⁻⁴ mbar) or dry hydrogen/argon at 771–816 °C with 0.03–0.08 mm joint clearance and no flux.
Can BAg-8a be formed, bent or molded?
Excellent cold ductility: drawn to fine wire, rolled to 0.05 mm foil and stamped into rings; anneal between heavy reductions.
BAg-8a 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 / ASTM B260, UNS P07723 | 71 – 73 | 72 |
| Lioxide-reducing (self-fluxing) addition | 0.15 – 0.3 | 0.22 |
| Other (total)total of all other elements, max | ≤ 0.15 | |
| Cdcadmium-free grade | ≤ 0 | 0 |
| Curemainder, nominally ~27.8% | balance |
What surface finishes work on BAg-8a?
As-brazed fillets are bright and need no cleaning; store filler in sealed dry packs because the lithium addition tarnishes quickly, and degrease before use rather than pickling.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAg-8a in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P07723
How much does BAg-8a cost?
BAg-8a is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAg-8a — frequently asked
What is BAg-8a used for?
BAg-8a is typically used for stainless steel furnace brazing without flux, vacuum and controlled-atmosphere brazing and honeycomb structure joining. In short: self-fluxing lithium eutectic; flux-free furnace brazing; rolls to 0.05 mm foil.
What is the yield strength of BAg-8a?
BAg-8a has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 59% of precious metal grades.
Is BAg-8a easy to machine?
Not especially — machinability is rated poor (30/100, worse than 86% of precious metal grades). Rarely machined; the soft eutectic is gummy — use sharp high-rake tools, light feeds and good lubrication if trimming preforms.
Can BAg-8a be welded?
Not readily — weldability is rated poor (20/100). Not a structural weld metal; it is the filler itself — braze in vacuum (10⁻⁴ mbar) or dry hydrogen/argon at 771–816 °C with 0.03–0.08 mm joint clearance and no flux.
What surface finishes work on BAg-8a?
As-brazed fillets are bright and need no cleaning; store filler in sealed dry packs because the lithium addition tarnishes quickly, and degrease before use rather than pickling.
Can BAg-8a be formed, bent or molded?
Excellent cold ductility: drawn to fine wire, rolled to 0.05 mm foil and stamped into rings; anneal between heavy reductions.
What is the maximum service temperature of BAg-8a?
BAg-8a is rated for continuous use to about 370°C (698 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAg-8a cost?
BAg-8a is a high-cost precious metal ($$$$), 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 A5.8/A5.8M — Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- ASTM B260 — Standard Specification for Brazing Filler Metal — ASTM International (2020)
- Brazing Handbook, 5th ed. — American Welding Society (2007)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
- Silver brazing alloy technical data (Ag-Cu eutectic and Li-bearing grades) — Lucas-Milhaupt / Handy & Harman (2020)
- GB/T 10046 (2018)
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.