Precious Metal BVAg-30
UNS P07687
BVAg-30 is a low-vapor-pressure, zinc-free silver-copper based vacuum-service braze filler (UNS P07687) used where a higher-silver composition is required for clean vacuum furnace brazing.
Reference datasheet — BVAg-30 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
BVAg-30 tempers and conditions
BVAg-30 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 BVAg-30 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 / Strip, rolled and annealed | Supply form |
PREFORM | Stamped / wound preform | Supply form |
Wire-Ann | Wire / Rod, annealed | Supply form |
WIRE-CW | Wire, spring-hard | Supply form |
PASTE | Paste | Printing process |
POWDER | Atomised powder | Printing process |
What is BVAg-30?
BVAg-30 is a low-vapor-pressure, zinc-free silver-copper based vacuum-service braze filler (UNS P07687) used where a higher-silver composition is required for clean vacuum furnace brazing. It suits high-purity stainless steel assemblies and is stocked as annealed and cold-worked wire, foil, stamped preforms, powder and paste. As-brazed deposits are about 300 MPa tensile and 170 MPa yield with 25% elongation, 90 HB and a service limit near 400 °C. Its 810–900 °C braze range is higher than BVAg-29, so check base-metal heat-treat response; BVAg-8 is the lower-cost eutectic alternative. BVAg-30 has a density of 10.2 g/cm³ (0.368 lb/in³), lighter than 57% of precious metal grades. It melts at 807°C (1,485 °F). BVAg-30 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 64% of precious metal grades. Elongation at break is 25% and the elastic modulus is 95 GPa (13.8 Msi).
What is BVAg-30 used for?
- Vacuum furnace brazing of high-purity stainless steel assemblies
- Sealed vacuum chamber components
- Instrument and sensor subassemblies
- Vacuum flanges, feedthroughs and fittings
- Ring and washer preforms for sleeve joints
- Foil-shim joints on thin-wall tubing
Limitations
- Hard to polish — 70/100, worse than 76% of precious metal grades
BVAg-30 properties
Typical room-temperature values for BVAg-30-AS-BRAZED; bars are the position among precious metal grades.
Physical3
BVAg-30 has a density of 10.2 g/cm³ (0.368 lb/in³), lighter than 57% of precious metal grades. It melts at 807°C (1,485 °F).
Mechanical10
BVAg-30 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 64% of precious metal grades. Elongation at break is 25% and the elastic modulus is 95 GPa (13.8 Msi).
Thermal5
BVAg-30 is rated for continuous service to 400°C (752 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 60% of precious metal grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BVAg-30 conducts electricity at 25 % IACS, better than 64% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 70% of precious metal grades.
Sustainability3
Producing a kilogram of BVAg-30 takes about 3,500 MJ of energy and emits 250 kg of CO₂ — more than 57% of precious metal grades. Typical recycled content is 60%.
Manufacturability6
BVAg-30's machinability is fair (35/100, worse than 73% of precious metal grades); weldability poor (30/100); formability very good (80/100).
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. BVAg-30 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BVAg-30
Is BVAg-30 easy to machine?
Rarely machined; if trimming preforms use sharp carbide, high speed and light feeds to avoid smearing this soft precious alloy — collect all chips for refining.
Can BVAg-30 be welded?
Not a structural weld alloy; joining is by furnace brazing at 810–900 °C in vacuum (≤1×10⁻⁴ mbar) or dry hydrogen with no flux, gap 0.025–0.075 mm.
Can BVAg-30 be formed, bent or molded?
Very ductile — cold draws to fine wire and rolls to <50 µm foil with interstage anneals around 600–700 °C; stamps cleanly into rings and washers.
BVAg-30 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 |
|---|---|---|
| Agsilver | 68 – 69 | 68.5 |
| Pdpalladium — improves wetting and resists filler run-off | 4.5 – 5.5 | 5 |
| Znvacuum-grade high-vapour-pressure limit | ≤ 0 | |
| Cdvacuum-grade high-vapour-pressure limit | ≤ 0 | |
| Pvacuum-grade limit | ≤ 0 | |
| Other elements totalAWS A5.8 vacuum-grade total impurity limit | ≤ 0.15 | |
| Cu | balance |
What surface finishes work on BVAg-30?
Degrease and vacuum-bake before use; fillets can be lightly polished or passivated, and tarnish from sulphur exposure is removed with a mild silver cleaner rather than abrasive blasting.
Equivalent designations
Standards and trade names that resolve to Precious Metal BVAg-30 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P07687
How much does BVAg-30 cost?
BVAg-30 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.
BVAg-30 — frequently asked
What is BVAg-30 used for?
BVAg-30 is typically used for vacuum furnace brazing of high-purity stainless steel assemblies, sealed vacuum chamber components, instrument and sensor subassemblies, vacuum flanges, feedthroughs and fittings, ring and washer preforms for sleeve joints and foil-shim joints on thin-wall tubing. In short: high-silver vacuum filler; zinc-free, low outgassing; higher braze temperature range.
What is the yield strength of BVAg-30?
BVAg-30 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 64% of precious metal grades.
Is BVAg-30 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 73% of precious metal grades). Rarely machined; if trimming preforms use sharp carbide, high speed and light feeds to avoid smearing this soft precious alloy — collect all chips for refining.
Can BVAg-30 be welded?
Not readily — weldability is rated poor (30/100). Not a structural weld alloy; joining is by furnace brazing at 810–900 °C in vacuum (≤1×10⁻⁴ mbar) or dry hydrogen with no flux, gap 0.025–0.075 mm.
What surface finishes work on BVAg-30?
Degrease and vacuum-bake before use; fillets can be lightly polished or passivated, and tarnish from sulphur exposure is removed with a mild silver cleaner rather than abrasive blasting.
Can BVAg-30 be formed, bent or molded?
Very ductile — cold draws to fine wire and rolls to <50 µm foil with interstage anneals around 600–700 °C; stamps cleanly into rings and washers.
What is the maximum service temperature of BVAg-30?
BVAg-30 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.
How much does BVAg-30 cost?
BVAg-30 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 A5.8M/A5.8: Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- ASTM B260 — Standard Specification for Brazing Filler Metal — ASTM International (2020)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Brazing Filler Metals) — ASM International (1993)
- Brazing Handbook, 5th ed. — American Welding Society (2007)
- Silver-palladium-copper vacuum brazing filler (Palcusil 5 type) datasheet — Precious-metal filler producers (e.g. Umicore / Morgan / Lucas-Milhaupt) (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.