Precious Metal BVAg-29 CW-Hard
Supply condition
UNS P07627
CW-Hard = cold Drawn / Hard
Choose for wire and pre-formed rings that must hold shape and stay seated in the joint during handling and furnace loading.
Values for the CW-Hard condition
Other BVAg-29 tempers and conditions
BVAg-29 is listed in 3 conditions; see the grade overview at BVAg-29.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Standard supply condition for rolled foil, washers and stamped preforms that must conform to the joint gap without spring-back. | 120 | 230 | 30 | 66 HB | 21 % IACS |
AS-BRAZEDDefault solidified joint filler (vacuum/furnace cycle) | Pick for design data of the finished joint: cast dendritic Ag-Cu-In structure after a 715–845 °C vacuum braze cycle. | 150 | 255 | 22 | 85 HB | 20 % IACS |
CW-HardThis page Cold Drawn / Hard | Choose for wire and pre-formed rings that must hold shape and stay seated in the joint during handling and furnace loading. | 350 | 420 | 5 | 123 HB | 19 % IACS |
What is BVAg-29 CW-Hard?
BVAg-29 CW-Hard is BVAg-29 supplied in the CW-Hard condition — choose for wire and pre-formed rings that must hold shape and stay seated in the joint during handling and furnace loading. BVAg-29 CW-Hard has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 95% of precious metal grades. Elongation at break is 5% and the elastic modulus is 83 GPa (12 Msi). BVAg-29 CW-Hard has a density of 9.7 g/cm³ (0.35 lb/in³), lighter than 78% of precious metal grades. It melts at 605°C (1,121 °F). AS-BRAZED is the default condition FabDigit quotes; CW-Hard is available on request or by drawing note.
Advantages
- High strength — 350 MPa (50.8 ksi), better than 95% of precious metal grades
- Easy to machine — 55/100, better than 86% of precious metal grades
Limitations
- Limited ductility — 5%, worse than 93% of precious metal grades
- Limited formability — 35/100, worse than 92% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Difficult to weld — 20/100, worse than 86% of precious metal grades
- Hard to polish — 70/100, worse than 76% of precious metal grades
BVAg-29 CW-Hard properties
Typical room-temperature values for BVAg-29 CW-Hard; 19 are specific to this condition. Other listed values are BVAg-29 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BVAg-29 CW-Hard has a density of 9.7 g/cm³ (0.35 lb/in³), lighter than 78% of precious metal grades. It melts at 605°C (1,121 °F).
Mechanical13
BVAg-29 CW-Hard has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 95% of precious metal grades. Elongation at break is 5% and the elastic modulus is 83 GPa (12 Msi).
Thermal5
BVAg-29 CW-Hard is rated for continuous service to 200°C (392 °F). It conducts heat at 68 W/m·K (39.3 BTU/hr·ft·°F), worse than 65% of precious metal grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BVAg-29 CW-Hard conducts electricity at 19 % IACS, worse than 51% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 70% of precious metal grades.
Sustainability4
Producing a kilogram of BVAg-29 CW-Hard takes about 1,100 MJ of energy and emits 78 kg of CO₂ — less than 71% of precious metal grades. Typical recycled content is 40%.
Manufacturability7
BVAg-29 CW-Hard's machinability is good (55/100, better than 86% of precious metal grades); weldability poor (20/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BVAg-29 CW-Hard
Is BVAg-29 easy to machine?
Rarely machined; the alloy is soft and gummy — use sharp high-rake tools, light cuts and collect all chips for silver reclaim.
Can BVAg-29 be welded?
Not a weld consumable: apply as foil, wire, powder or paste with 0.025–0.075 mm joint clearance and braze at 715–845 °C under vacuum (10⁻⁴–10⁻⁵ mbar) or dry hydrogen, no flux needed.
Can BVAg-29 be formed, bent or molded?
Readily rolled to 25–100 µm foil and drawn to fine wire in the annealed state; interanneal to avoid cracking when stamping preforms.
What surface finishes work on BVAg-29?
Joints need only degreasing; silver fillets tarnish in sulphurous air and can be protected by nickel/gold plating or passivation of the surrounding base metal.
BVAg-29 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 content per AWS A5.8 BVAg-29 | 60.5 – 62.5 | 61.5 |
| Inmelting-point depressant, replaces Zn/Cd | 13.5 – 15.5 | 14.5 |
| Cdvacuum-grade high-vapor-pressure element limit | ≤ 0 | — |
| Znvacuum-grade limit | ≤ 0 | — |
| Pimpurity limit | ≤ 0 | — |
| Other (total)total other elements | ≤ 0.15 | — |
| Cu | balance | — |
BVAg-29 CW-Hard — frequently asked
What is BVAg-29 CW-Hard used for?
BVAg-29 CW-Hard is typically used for vacuum furnace brazing of stainless steel assemblies, nickel-alloy subassemblies, sealed instrument and sensor housings, vacuum system fittings and flanges, paste-applied joints on thin-wall tubing and foil and ring preforms for sleeve joints. In short: zinc- and cadmium-free; vacuum-purity BAg filler; clean flux-free joints.
What is the yield strength of BVAg-29 CW-Hard?
BVAg-29 CW-Hard has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 95% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is BVAg-29 CW-Hard easy to machine?
Reasonably — machinability is rated good (55/100, better than 86% of precious metal grades). Rarely machined; the alloy is soft and gummy — use sharp high-rake tools, light cuts and collect all chips for silver reclaim.
Can BVAg-29 CW-Hard be welded?
Not readily — weldability is rated poor (20/100). Not a weld consumable: apply as foil, wire, powder or paste with 0.025–0.075 mm joint clearance and braze at 715–845 °C under vacuum (10⁻⁴–10⁻⁵ mbar) or dry hydrogen, no flux needed.
What surface finishes work on BVAg-29 CW-Hard?
Joints need only degreasing; silver fillets tarnish in sulphurous air and can be protected by nickel/gold plating or passivation of the surrounding base metal.
Can BVAg-29 CW-Hard be formed, bent or molded?
Readily rolled to 25–100 µm foil and drawn to fine wire in the annealed state; interanneal to avoid cracking when stamping preforms.
What is the maximum service temperature of BVAg-29 CW-Hard?
BVAg-29 CW-Hard is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BVAg-29 AS-BRAZED and BVAg-29 CW-Hard?
AS-BRAZED is the default condition — pick for design data of the finished joint: cast dendritic Ag-Cu-In structure after a 715–845 °C vacuum braze cycle. CW-Hard: choose for wire and pre-formed rings that must hold shape and stay seated in the joint during handling and furnace loading. Yield strength is 150 MPa in AS-BRAZED versus 350 MPa in CW-Hard.
Sources
- AWS A5.8M/A5.8 Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- SAE/AMS 3130-series & UNS P07xxx precious-metal filler designations — SAE International / ASTM-SAE UNS (2018)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Brazing Filler Metals) — ASM International (1993)
- AWS Brazing Handbook, 5th ed. — American Welding Society (2007)
- Vacuum-grade Ag-Cu-In brazing alloy (foil, wire, powder) data — Morgan Advanced Materials (Wesgo Metals) (2022)
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.