Precious Metal BAu-2-ANN (Annealed)
Heat-treated state · default condition
UNS P00800
Pick this soft wire, ribbon or stamped preform ring, the usual supply state, for easy assembly and automatic feeding; 30% elongation and 14% IACS come with only 200 MPa yield.
Values for the ANN condition
Other BAu-2 tempers and conditions
BAu-2 is listed in 3 conditions; see the grade overview at BAu-2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As built (as printed) | Use these values to assess the real joint: the seam solidifies as a fine-grained cast structure at 340 MPa tensile and 400 °C maximum service, sensitive to gap and base-metal diffusion. | 180 | 340 | 20 | 143 HB | 14 % IACS |
ANNDefaultThis page Annealed | Pick this soft wire, ribbon or stamped preform ring, the usual supply state, for easy assembly and automatic feeding; 30% elongation and 14% IACS come with only 200 MPa yield. | 200 | 380 | 30 | 138 HB | 14 % IACS |
Hardened | Choose the as-drawn or cold-rolled, unannealed wire and strip when stiffness aids precise shearing of small preforms; 620 MPa tensile comes with 4% elongation and poor bend formability. | 500 | 620 | 4 | 17 HRC | 13 % IACS |
What is BAu-2-ANN?
BAu-2-ANN is BAu-2 heat treated to ANN — pick this soft wire, ribbon or stamped preform ring, the usual supply state, for easy assembly and automatic feeding; 30% elongation and 14% IACS come with only 200 MPa yield. BAu-2-ANN has a yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades. Elongation at break is 30% and the elastic modulus is 90 GPa (13.1 Msi). BAu-2-ANN has a density of 15.9 g/cm³ (0.574 lb/in³), heavier than 81% of precious metal grades. It melts at 889°C (1,632 °F).
Advantages
- Good corrosion resistance — 95/100, better than 82% of precious metal grades
Limitations
- High embodied carbon — 15,000 kg CO₂/kg, worse than 94% of precious metal grades
- Heavy — 15.9 g/cm³ (0.574 lb/in³), worse than 81% of precious metal grades
- Poor heat conductor — 50 W/m·K (28.9 BTU/hr·ft·°F), worse than 79% of precious metal grades
BAu-2-ANN properties
Typical room-temperature values for BAu-2-ANN; 19 are specific to this condition. Other listed values are BAu-2 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BAu-2-ANN has a density of 15.9 g/cm³ (0.574 lb/in³), heavier than 81% of precious metal grades. It melts at 889°C (1,632 °F).
Mechanical13
BAu-2-ANN has a yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades. Elongation at break is 30% and the elastic modulus is 90 GPa (13.1 Msi).
Thermal6
BAu-2-ANN is rated for continuous service to 400°C (752 °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 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
BAu-2-ANN conducts electricity at 14 % IACS, worse than 70% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (95/100), better than 82% of precious metal grades.
Sustainability4
Producing a kilogram of BAu-2-ANN takes about 210,000 MJ of energy and emits 15,000 kg of CO₂ — more than 88% of precious metal grades. Typical recycled content is 85%.
Manufacturability7
BAu-2-ANN's machinability is fair (35/100, worse than 73% of precious metal grades); weldability good (55/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BAu-2-ANN
Is BAu-2 easy to machine?
Extremely gummy; use sharp, high positive rake carbide tools with small depths of cut. All chips must be collected separately for precious-metal recovery.
Can BAu-2 be welded?
Used as a braze filler; it is not fusion welded. Joint cleanliness and a vacuum or hydrogen reducing atmosphere matter more than any welding parameter.
Can BAu-2 be formed, bent or molded?
Very ductile in the annealed temper (formability score 85): draws to fine wire, rolls to foil and stamps into preform rings. Intermediate anneal at 600-700 °C after cold work.
What surface finishes work on BAu-2?
The gold fillet resists oxidation as brazed and can be ultrasonically cleaned directly. No plating is needed; light polishing is optional, and chlorinated cleaners should be avoided.
BAu-2 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-2 / UNS P00800 | 79.5 – 80.5 | 80 |
| Other (total)upper limit on total impurities | ≤ 0.15 | — |
| Cu | balance | — |
BAu-2-ANN — frequently asked
What is BAu-2-ANN used for?
BAu-2-ANN is typically used for hermetic electronic packages, aerospace brazed assemblies, nuclear component joining and high-vacuum equipment. In short: most oxidation-resistant BAu filler; very ductile brazed joints; highest gold cost.
What is the yield strength of BAu-2-ANN?
BAu-2-ANN has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is BAu-2-ANN easy to machine?
Not especially — machinability is rated fair (35/100, worse than 73% of precious metal grades). Extremely gummy; use sharp, high positive rake carbide tools with small depths of cut. All chips must be collected separately for precious-metal recovery.
Can BAu-2-ANN be welded?
Yes — weldability is rated good (55/100). Used as a braze filler; it is not fusion welded. Joint cleanliness and a vacuum or hydrogen reducing atmosphere matter more than any welding parameter.
What surface finishes work on BAu-2-ANN?
The gold fillet resists oxidation as brazed and can be ultrasonically cleaned directly. No plating is needed; light polishing is optional, and chlorinated cleaners should be avoided.
Can BAu-2-ANN be formed, bent or molded?
Very ductile in the annealed temper (formability score 85): draws to fine wire, rolls to foil and stamps into preform rings. Intermediate anneal at 600-700 °C after cold work.
What is the maximum service temperature of BAu-2-ANN?
BAu-2-ANN is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BAu-2-ANN and BAu-2-H?
ANN is the default condition — pick this soft wire, ribbon or stamped preform ring, the usual supply state, for easy assembly and automatic feeding; 30% elongation and 14% IACS come with only 200 MPa yield. H: choose the as-drawn or cold-rolled, unannealed wire and strip when stiffness aids precise shearing of small preforms; 620 MPa tensile comes with 4% elongation and poor bend formability. Yield strength is 200 MPa in ANN versus 500 MPa in H.
Sources
- AWS A5.8/A5.8M — Specification for Filler Metals for Brazing and Braze Welding — AWS (2019)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (Brazing Filler Metals) — ASM International (1993)
- ASM Handbook Vol.2 — Properties of Precious Metals and Alloys — ASM International (1990)
- Gold-copper brazing alloy (80Au-20Cu) technical data (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.