Precious Metal BAu-6
UNS P00700
BAu-6 is a 70%Au-30%Cu gold-copper braze filler (UNS P00700) whose melting range sits between BAu-1 and BAu-2, giving general-purpose precious-metal joints at moderate gold cost with good flow.
Reference datasheet — BAu-6 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.
Values for the AS-BRAZED condition
BAu-6 tempers and conditions
BAu-6 is supplied in one standard condition, AS-BRAZED. AS-BRAZED is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways BAu-6 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FOIL | Foil / Ribbon | Supply form |
PREFORM | Stamped rings, washers and shaped preforms | Supply form |
WIRE | Annealed drawn wire / rod for face-fed and preform winding | Supply form |
PASTE | Powder in organic binder for dispensing or screen printing | Printing process |
POWDER | Gas-atomised, typically −100/+325 mesh | Printing process |
What is BAu-6?
BAu-6 is a 70%Au-30%Cu gold-copper braze filler (UNS P00700) whose melting range sits between BAu-1 and BAu-2, giving general-purpose precious-metal joints at moderate gold cost with good flow. It is stocked as wire, foil, stamped preforms, powder and paste for electronic, instrument and aerospace assemblies. As-brazed properties are about 500 MPa tensile with 15% elongation and a maximum service temperature of 800 °C. For sustained oxidizing service above that range, the Au-Ni grade BAu-4 is the usual substitute. BAu-6 has a density of 14.8 g/cm³ (0.535 lb/in³), heavier than 74% of precious metal grades. It melts at 1,007°C (1,845 °F). BAu-6 has a tensile strength of 500 MPa (72.5 ksi), stronger than 90% of precious metal grades. Elongation at break is 15% and the elastic modulus is 105 GPa (15.2 Msi).
What is BAu-6 used for?
- Electronic component brazing
- Instrument and sensor assemblies
- Precision mechanical joints
- Aerospace hardware
Advantages
- High service temperature — 800°C (1,472 °F), better than 90% of precious metal grades
- Good corrosion resistance — 93/100, better than 77% of precious metal grades
Limitations
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 89% of precious metal grades
- High embodied carbon — 14,000 kg CO₂/kg, worse than 88% of precious metal grades
- Limited ductility — 15%, worse than 86% of precious metal grades
- Limited formability — 65/100, worse than 86% of precious metal grades
BAu-6 properties
Typical room-temperature values for BAu-6-AS-BRAZED; bars are the position among precious metal grades.
Physical3
BAu-6 has a density of 14.8 g/cm³ (0.535 lb/in³), heavier than 74% of precious metal grades. It melts at 1,007°C (1,845 °F).
Mechanical6
BAu-6 has a tensile strength of 500 MPa (72.5 ksi), stronger than 90% of precious metal grades. Elongation at break is 15% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
BAu-6 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 89% of precious metal grades. Thermal expansion is 15 µm/m·K (8.33 µin/in·°F).
Electrical2
BAu-6 has an electrical resistivity of 3×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (93/100), better than 77% of precious metal grades.
Sustainability4
Producing a kilogram of BAu-6 takes about 200,000 MJ of energy and emits 14,000 kg of CO₂ — more than 85% of precious metal grades. Typical recycled content is 70%.
Manufacturability6
BAu-6's machinability is fair (35/100, worse than 73% of precious metal grades); weldability fair (40/100); formability good (65/100).
Common Calculations4
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. BAu-6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAu-6
Is BAu-6 easy to machine?
Rarely machined; if required, use sharp carbide/HSS tools, light feeds and flood coolant, and capture all chips and swarf for precious-metal recovery.
Can BAu-6 be welded?
Not a structural weld filler — it is applied by vacuum, dry-hydrogen or partial-pressure furnace brazing at 1016–1093 °C with short hold times to limit nickel erosion of thin base metals.
Can BAu-6 be formed, bent or molded?
Supplied as drawn wire, rolled foil, stamped preforms, powder and paste; interstage vacuum annealing is needed because the Au-Ni-Pd solid solution work hardens quickly.
BAu-6 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 |
|---|---|---|
| AuAWS A5.8 BAu-6 (UNS P00700) | 69.5 – 70.5 | 70 |
| Pd | 7.5 – 8.5 | 8 |
| Other (total)total of all other elements, incl. residuals | ≤ 0.15 | |
| Ni | balance |
What surface finishes work on BAu-6?
Joints are self-fluxing in vacuum and need no post-braze cleaning beyond light abrasive or ultrasonic work; the noble deposit polishes brightly and takes plating without further activation.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAu-6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P00700
- Also called
- AWS BAu-6
How much does BAu-6 cost?
BAu-6 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAu-6 — frequently asked
What is BAu-6 used for?
BAu-6 is typically used for electronic component brazing, instrument and sensor assemblies, precision mechanical joints and aerospace hardware. In short: mid-range Au-Cu braze; good flow, moderate cost; general-purpose precious filler.
What is the tensile strength of BAu-6?
BAu-6 has a typical tensile strength of 500 MPa (72.5 ksi) — stronger than 90% of precious metal grades.
Is BAu-6 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 73% of precious metal grades). Rarely machined; if required, use sharp carbide/HSS tools, light feeds and flood coolant, and capture all chips and swarf for precious-metal recovery.
Can BAu-6 be welded?
With care — weldability is rated fair (40/100). Not a structural weld filler — it is applied by vacuum, dry-hydrogen or partial-pressure furnace brazing at 1016–1093 °C with short hold times to limit nickel erosion of thin base metals.
What surface finishes work on BAu-6?
Joints are self-fluxing in vacuum and need no post-braze cleaning beyond light abrasive or ultrasonic work; the noble deposit polishes brightly and takes plating without further activation.
Can BAu-6 be formed, bent or molded?
Supplied as drawn wire, rolled foil, stamped preforms, powder and paste; interstage vacuum annealing is needed because the Au-Ni-Pd solid solution work hardens quickly.
What is the maximum service temperature of BAu-6?
BAu-6 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAu-6 cost?
BAu-6 is a high-cost precious metal ($$$$), 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)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (brazing filler metals) — ASM International (1993)
- Gold-based vacuum brazing filler metals (BAu series) datasheets — Morgan Advanced Materials (Wesgo) / Lucas-Milhaupt (2022)
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.