Precious Metal BAu-3
UNS P00350
BAu-3 (P00350) is a 35% Au-62% Ag-3% Ni gold-silver-nickel braze filler, with the nickel addition improving wetting on nickel-base alloys and stainless steels.
Reference datasheet — BAu-3 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.
BAu-3 tempers and conditions
BAu-3 is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BAu-3 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PREFORM | Rings, washers and stamped shapes | Supply form |
STRIP | Strip / foil | Supply form |
WIREDefault | Wire / rod | Supply form |
PASTE | Powder plus organic binder/flux vehicle | Printing process |
POWDER | Atomized filler powder | Printing process |
What is BAu-3?
BAu-3 (P00350) is a 35% Au-62% Ag-3% Ni gold-silver-nickel braze filler, with the nickel addition improving wetting on nickel-base alloys and stainless steels. As-brazed strength is about 430 MPa tensile with 18% elongation, and the alloy is supplied as wire, strip, stamped preforms, powder and paste, with a formability score of 70. It brazes at roughly 1000-1090 °C in vacuum, dry hydrogen or inert gas with 0.03-0.08 mm joint clearance. Sulfur-bearing media stain or attack the silver-rich fillet; BAu-2 is the alternative where higher gold and oxidation resistance are needed. BAu-3 has a density of 11 g/cm³ (0.397 lb/in³), heavier than 58% of precious metal grades. It melts at 975°C (1,787 °F). BAu-3 has a tensile strength of 400 MPa (58 ksi), stronger than 55% of precious metal grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi).
What is BAu-3 used for?
- Stainless steel and nickel-alloy brazing
- Electrical contact assemblies
- Instrument component joining
- Sensor housings
Advantages
- High service temperature — 500°C (932 °F), better than 79% of precious metal grades
Limitations
- Poor heat conductor — 50 W/m·K (28.9 BTU/hr·ft·°F), worse than 79% of precious metal grades
- Limited formability — 70/100, worse than 78% of precious metal grades
- Limited ductility — 20%, worse than 77% of precious metal grades
- Low electrical conductivity — 11 % IACS, worse than 75% of precious metal grades
BAu-3 properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
BAu-3 has a density of 11 g/cm³ (0.397 lb/in³), heavier than 58% of precious metal grades. It melts at 975°C (1,787 °F).
Mechanical8
BAu-3 has a tensile strength of 400 MPa (58 ksi), stronger than 55% of precious metal grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
BAu-3 is rated for continuous service to 500°C (932 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), worse than 79% of precious metal grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
BAu-3 conducts electricity at 11 % IACS, worse than 75% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 53% of precious metal grades.
Sustainability4
Producing a kilogram of BAu-3 takes about 92,000 MJ of energy and emits 6,300 kg of CO₂ — more than 66% of precious metal grades. Typical recycled content is 60%.
Manufacturability4
BAu-3's formability very good (70/100).
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-3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAu-3
Is BAu-3 easy to machine?
Filler alloy is not a structural machining stock; wire/foil is cut, sheared or stamped, and joints are cleaned by light grinding only to avoid smearing the soft noble metal.
Can BAu-3 be welded?
Not a weldable structural alloy — it is a brazing filler; braze in vacuum, dry hydrogen or inert gas at about 1000–1090 °C with tight 0.03–0.08 mm joint clearance.
Can BAu-3 be formed, bent or molded?
Very ductile FCC alloy: readily drawn to fine wire, rolled to foil and stamped into rings/washers, with interstage annealing after heavy reductions.
BAu-3 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 |
|---|---|---|
| AuUNS P00350 | 34.5 – 35.5 | 35 |
| Niimproves wetting, limits base-metal erosion | 2.5 – 3.5 | 3 |
| Other (total)total of all other elements per AWS A5.8 | ≤ 0.15 | |
| Cu | balance |
What surface finishes work on BAu-3?
Joints need no plating; degrease and pickle base metals before brazing, and avoid sulfur-bearing fluxes or cutting oils that stain the Cu/Ni-bearing fillet.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAu-3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P00350
- Also called
- AWS BAu-3
How much does BAu-3 cost?
BAu-3 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAu-3 — frequently asked
What is BAu-3 used for?
BAu-3 is typically used for stainless steel and nickel-alloy brazing, electrical contact assemblies, instrument component joining and sensor housings. In short: best wetting on stainless; moderate melting range; silver-bearing, sulfur sensitive.
What is the tensile strength of BAu-3?
BAu-3 has a typical tensile strength of 400 MPa (58 ksi) — stronger than 55% of precious metal grades.
Is BAu-3 easy to machine?
Filler alloy is not a structural machining stock; wire/foil is cut, sheared or stamped, and joints are cleaned by light grinding only to avoid smearing the soft noble metal.
Can BAu-3 be welded?
Not a weldable structural alloy — it is a brazing filler; braze in vacuum, dry hydrogen or inert gas at about 1000–1090 °C with tight 0.03–0.08 mm joint clearance.
What surface finishes work on BAu-3?
Joints need no plating; degrease and pickle base metals before brazing, and avoid sulfur-bearing fluxes or cutting oils that stain the Cu/Ni-bearing fillet.
Can BAu-3 be formed, bent or molded?
Very ductile FCC alloy: readily drawn to fine wire, rolled to foil and stamped into rings/washers, with interstage annealing after heavy reductions.
What is the maximum service temperature of BAu-3?
BAu-3 is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAu-3 cost?
BAu-3 is a high-cost precious metal ($$$$), 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 brazing filler metal datasheets (Au-Cu-Ni family) — precious-metal brazing alloy producers (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.