Precious Metal BVAg-31
UNS P07587
BVAg-31 is a zinc-free silver–copper brazing filler (UNS P07587) in the BVAg vacuum-grade family, with volatile elements held low so it can run in vacuum and dry-hydrogen furnaces.
Reference datasheet — BVAg-31 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 Annealed condition
BVAg-31 tempers and conditions
BVAg-31 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
solidified filler in the joint | Design condition for joint strength calculations after a vacuum braze cycle at 870–925 °C. | 230 | 400 | 18 | 115 HB | 10.5 % IACS |
AnnealedDefault vacuum-melted wire / rod, soft temper | Default stocked form: soft drawn wire or rod for hand feeding, automatic wire dispensing and ring forming. | 240 | 420 | 22 | 110 HB | 11 % IACS |
Supply forms, finishes and certifications
Ways BVAg-31 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 | Rolled foil / ribbon | Supply form |
H-WIRE | As-drawn (hard) wire | Supply form |
PREFORM | Stamped preform | Supply form |
PASTE | Braze paste | Printing process |
POWDER | Atomized powder | Printing process |
What is BVAg-31?
BVAg-31 is a zinc-free silver–copper brazing filler (UNS P07587) in the BVAg vacuum-grade family, with volatile elements held low so it can run in vacuum and dry-hydrogen furnaces. Engineers select it for stainless steel and superalloy joints where zinc- or cadmium-bearing fillers would outgas and contaminate the furnace; it is stocked as annealed and hard-drawn wire, foil, stamped preforms, powder and paste. As-brazed stock runs about 420 MPa tensile, 240 MPa yield and 22% elongation. Brazing near 870–925 °C limits base-metal choice, and silver content makes it costly against nickel or copper fillers; BVAg-32 covers the higher-temperature end of the series. BVAg-31 has a density of 10.1 g/cm³ (0.365 lb/in³), lighter than 61% of precious metal grades. It melts at 824°C (1,515 °F). BVAg-31 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 73% of precious metal grades. Elongation at break is 22% and the elastic modulus is 100 GPa (14.5 Msi).
What is BVAg-31 used for?
- Vacuum furnace brazing of stainless steel assemblies
- Superalloy joints in turbine and engine hardware
- Vacuum-tight instrument and sensor housings
- Stainless steel heat exchanger cores
- Tube-to-fitting preform rings
- RF and waveguide component brazing
Limitations
- Low electrical conductivity — 11 % IACS, worse than 75% of precious metal grades
BVAg-31 properties
Typical room-temperature values for BVAg-31-Annealed; bars are the position among precious metal grades.
Physical3
BVAg-31 has a density of 10.1 g/cm³ (0.365 lb/in³), lighter than 61% of precious metal grades. It melts at 824°C (1,515 °F).
Mechanical13
BVAg-31 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 73% of precious metal grades. Elongation at break is 22% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
BVAg-31 is rated for continuous service to 450°C (842 °F). It conducts heat at 70 W/m·K (40.4 BTU/hr·ft·°F), worse than 63% of precious metal grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
BVAg-31 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.
Sustainability3
Producing a kilogram of BVAg-31 takes about 4,400 MJ of energy and emits 420 kg of CO₂ — more than 58% of precious metal grades. Typical recycled content is 50%.
Manufacturability8
BVAg-31's machinability is fair (40/100, worse than 60% 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-31 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BVAg-31
Is BVAg-31 easy to machine?
Rarely machined; the alloy is soft and gummy — use sharp, polished high-rake tools and collect all chips as precious-metal scrap.
Can BVAg-31 be welded?
Not a weld filler; joints are made by vacuum or dry-hydrogen furnace brazing at roughly 870–925 °C with a short soak to limit erosion of thin base metals.
Can BVAg-31 be formed, bent or molded?
Excellent cold formability in the annealed state — drawn to fine wire, rolled to 25 µm foil and stamped into rings; interstage anneal near 650–700 °C in inert atmosphere.
BVAg-31 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 |
|---|---|---|
| AgAWS A5.8 BVAg-31 / UNS P07587 | 58 – 59 | 58.5 |
| Pdraises melting range and high-temperature joint strength | 9.5 – 10.5 | 10 |
| Znvacuum-grade high-vapor-pressure element limit | ≤ 0 | |
| Cdvacuum-grade limit | ≤ 0 | |
| Pvacuum-grade limit | ≤ 0 | |
| Other (total)total of other elements | ≤ 0.15 | |
| Cu | balance |
What surface finishes work on BVAg-31?
Fluxless brazing in vacuum leaves a bright, clean fillet needing no cleaning; if flux-brazed in air, remove residues with hot water/citric rinse before plating or passivation.
Equivalent designations
Standards and trade names that resolve to Precious Metal BVAg-31 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P07587
How much does BVAg-31 cost?
BVAg-31 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-31 — frequently asked
What is BVAg-31 used for?
BVAg-31 is typically used for vacuum furnace brazing of stainless steel assemblies, superalloy joints in turbine and engine hardware, vacuum-tight instrument and sensor housings, stainless steel heat exchanger cores, tube-to-fitting preform rings and RF and waveguide component brazing. In short: zinc-free vacuum silver braze; lower-temperature BVAg option; flux-free, clean fillets.
What is the yield strength of BVAg-31?
BVAg-31 has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 73% of precious metal grades. Strength varies by condition: see the 2 listed tempers.
Is BVAg-31 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 60% of precious metal grades). Rarely machined; the alloy is soft and gummy — use sharp, polished high-rake tools and collect all chips as precious-metal scrap.
Can BVAg-31 be welded?
Not readily — weldability is rated poor (30/100). Not a weld filler; joints are made by vacuum or dry-hydrogen furnace brazing at roughly 870–925 °C with a short soak to limit erosion of thin base metals.
What surface finishes work on BVAg-31?
Fluxless brazing in vacuum leaves a bright, clean fillet needing no cleaning; if flux-brazed in air, remove residues with hot water/citric rinse before plating or passivation.
Can BVAg-31 be formed, bent or molded?
Excellent cold formability in the annealed state — drawn to fine wire, rolled to 25 µm foil and stamped into rings; interstage anneal near 650–700 °C in inert atmosphere.
What is the maximum service temperature of BVAg-31?
BVAg-31 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BVAg-31 cost?
BVAg-31 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)
- Brazing Handbook, 5th ed. — American Welding Society (2007)
- Palladium-bearing silver braze alloy (Palcusil 10 type) technical data — brazing filler metal producers (2022)
- GB/T 10046 (2018)
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.