Precious Metal BVAg-8 AS-BRAZED
Heat-treated state
UNS P07727
Properties of the finished lap/butt joint rather than of the filler stock — use for joint design allowables.
Values for the AS-BRAZED condition
What is BVAg-8 AS-BRAZED?
BVAg-8 AS-BRAZED is BVAg-8 heat treated to AS-BRAZED — properties of the finished lap/butt joint rather than of the filler stock — use for joint design allowables. BVAg-8 AS-BRAZED has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 76% of precious metal grades. Elongation at break is 25% and the elastic modulus is 85 GPa (12.3 Msi). BVAg-8 AS-BRAZED has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 780°C (1,436 °F).
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
- Low strength — 120 MPa (17.4 ksi), worse than 76% of precious metal grades
BVAg-8 AS-BRAZED properties
Typical room-temperature values for BVAg-8 AS-BRAZED; 4 are specific to this condition. Other listed values are BVAg-8 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BVAg-8 AS-BRAZED has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 780°C (1,436 °F).
Mechanical10
BVAg-8 AS-BRAZED has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 76% of precious metal grades. Elongation at break is 25% and the elastic modulus is 85 GPa (12.3 Msi).
Thermal6
BVAg-8 AS-BRAZED 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 19.7 µm/m·K (10.9 µin/in·°F).
Electrical3
BVAg-8 AS-BRAZED conducts electricity at 87 % IACS, better than 93% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), worse than 66% of precious metal grades.
Sustainability4
Producing a kilogram of BVAg-8 AS-BRAZED takes about 1,200 MJ of energy and emits 110 kg of CO₂ — less than 66% of precious metal grades. Typical recycled content is 40%.
Manufacturability6
BVAg-8 AS-BRAZED's machinability is fair (35/100, worse than 73% of precious metal grades); formability excellent (88/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BVAg-8 AS-BRAZED
Is BVAg-8 easy to machine?
Rarely machined; the eutectic is soft and gummy — stamping or shearing of foil into preforms is preferred over turning or milling.
Can BVAg-8 be welded?
Not a structural weld filler; joint is made by vacuum or dry-hydrogen furnace brazing at 780–900 °C with 0.03–0.10 mm diametral clearance and no flux.
Can BVAg-8 be formed, bent or molded?
Excellent cold formability — drawn to fine wire, rolled to 0.05 mm foil and stamped into rings and washers with interstage annealing.
What surface finishes work on BVAg-8?
Handle with clean gloves and degrease before loading; as-brazed fillets are bright and need no finishing, but sulfur-bearing atmospheres will tarnish them, so store preforms sealed.
BVAg-8 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 |
|---|---|---|
| Ageutectic composition | 71 – 73 | 72 |
| Znvacuum-grade high-vapor-pressure limit | ≤ 0 | |
| Cdvacuum-grade high-vapor-pressure limit | ≤ 0 | |
| P | ≤ 0 | |
| Pb | ≤ 0 | |
| Other (total)total of all other elements | ≤ 0.15 | |
| Cu | balance |
BVAg-8 AS-BRAZED — frequently asked
What is BVAg-8 AS-BRAZED used for?
BVAg-8 AS-BRAZED is typically used for vacuum furnace brazing, electron tube and sensor assemblies and stainless steel vacuum components. In short: eutectic 72Ag-28Cu filler; low-outgassing vacuum grade; flux-free furnace brazing.
What is the yield strength of BVAg-8 AS-BRAZED?
BVAg-8 AS-BRAZED has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 76% of precious metal grades.
Is BVAg-8 AS-BRAZED easy to machine?
Not especially — machinability is rated fair (35/100, worse than 73% of precious metal grades). Rarely machined; the eutectic is soft and gummy — stamping or shearing of foil into preforms is preferred over turning or milling.
Can BVAg-8 AS-BRAZED be welded?
Not a structural weld filler; joint is made by vacuum or dry-hydrogen furnace brazing at 780–900 °C with 0.03–0.10 mm diametral clearance and no flux.
What surface finishes work on BVAg-8 AS-BRAZED?
Handle with clean gloves and degrease before loading; as-brazed fillets are bright and need no finishing, but sulfur-bearing atmospheres will tarnish them, so store preforms sealed.
Can BVAg-8 AS-BRAZED be formed, bent or molded?
Excellent cold formability — drawn to fine wire, rolled to 0.05 mm foil and stamped into rings and washers with interstage annealing.
What is the maximum service temperature of BVAg-8 AS-BRAZED?
BVAg-8 AS-BRAZED 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.
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)
- Brazing Handbook, 5th ed. — American Welding Society (2007)
- Silver-copper eutectic vacuum-grade filler metal datasheets (Lucas-Milhaupt / Umicore / ) — various producers (2023)
- GB/T 10046 — SAC (2018)
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.