Precious Metal BAg-8 Hard
Supply condition
GB BAg72Cu
Hard = hard drawn
Pick hard-drawn wire when an automatic feeder or stamping blank needs stiffness: 620 MPa tensile and 130 HB, with elongation dropping to 4% and formability limited.
Values for the Hard condition
Other BAg-8 tempers and conditions
BAg-8 is listed in 3 conditions; see the grade overview at BAg-8.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-brazed joint deposit (cast eutectic structure) | Use these as-solidified eutectic values (lamellar Ag-rich/Cu-rich phases, 330 MPa, 12% elongation, 355 W/m·K, 400 °C max) when assessing the finished joint rather than the supplied filler. | 140 | 330 | 12 | 84 HB | 85 % IACS |
AnnealedDefault soft wire / rod / strip as supplied | Default stocked form: soft wire, rod or strip at 380 MPa tensile and 20% elongation, easy to bend into preformed rings and hand-feed, but too limp for automatic feeders. | 160 | 380 | 20 | 65 HB | 87 % IACS |
HardThis page Hard drawn | Pick hard-drawn wire when an automatic feeder or stamping blank needs stiffness: 620 MPa tensile and 130 HB, with elongation dropping to 4% and formability limited. | 480 | 620 | 4 | 130 HB | 84 % IACS |
What is BAg-8 Hard?
BAg-8 Hard is BAg-8 supplied in the Hard condition — pick hard-drawn wire when an automatic feeder or stamping blank needs stiffness: 620 MPa tensile and 130 HB, with elongation dropping to 4% and formability limited. BAg-8 Hard has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 97% of precious metal grades. Elongation at break is 4% and the elastic modulus is 90 GPa (13.1 Msi). BAg-8 Hard has a density of 10 g/cm³ (0.361 lb/in³), lighter than 65% of precious metal grades. It melts at 780°C (1,436 °F). Annealed is the default condition FabDigit quotes; Hard is available on request or by drawing note.
Advantages
- Easy to machine — 65/100, better than 100% of precious metal grades
- High strength — 480 MPa (69.6 ksi), better than 97% of precious metal grades
- Conducts heat well — 345 W/m·K (199.3 BTU/hr·ft·°F), better than 88% of precious metal grades
- High electrical conductivity — 84 % IACS, better than 87% of precious metal grades
Limitations
- Limited ductility — 4%, worse than 93% of precious metal grades
- Limited formability — 40/100, worse than 91% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Difficult to weld — 28/100, worse than 76% of precious metal grades
BAg-8 Hard properties
Typical room-temperature values for BAg-8 Hard; 19 are specific to this condition. Other listed values are BAg-8 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BAg-8 Hard has a density of 10 g/cm³ (0.361 lb/in³), lighter than 65% of precious metal grades. It melts at 780°C (1,436 °F).
Mechanical13
BAg-8 Hard has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 97% of precious metal grades. Elongation at break is 4% and the elastic modulus is 90 GPa (13.1 Msi).
Thermal6
BAg-8 Hard is rated for continuous service to 200°C (392 °F). It conducts heat at 345 W/m·K (199.3 BTU/hr·ft·°F), better than 88% of precious metal grades. Thermal expansion is 19.6 µm/m·K (10.9 µin/in·°F).
Electrical3
BAg-8 Hard conducts electricity at 84 % IACS, better than 87% 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 BAg-8 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 45%.
Manufacturability7
BAg-8 Hard's machinability is good (65/100, better than 100% of precious metal grades); weldability poor (28/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BAg-8 Hard
Is BAg-8 easy to machine?
Soft and gummy: turning preforms requires sharp, high-rake tooling, high spindle speed and ample lubricant to prevent smearing and built-up edge.
Can BAg-8 be welded?
This is a brazing filler metal. Furnace or vacuum braze at roughly 800–870 °C; the eutectic has no mushy range, so heat quickly and uniformly and avoid long soaks that soften the base metal.
Can BAg-8 be formed, bent or molded?
Annealed material is ductile enough to draw to wire, roll to foil and stamp into rings and shims. After hard drawing, interanneal at about 600 °C with a rapid cool to restore ductility.
What surface finishes work on BAg-8?
Pickle joints after brazing to remove flux residue. The copper-rich phase darkens in sulphide atmospheres, so plate cosmetic joints with nickel or rhodium.
BAg-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 |
|---|---|---|
| AgAWS A5.8/A5.8M, UNS P07720 | 71 – 73 | 72 |
| Znimpurity | ≤ 0.05 | — |
| Cdcadmium-free grade | ≤ 0.01 | — |
| Pimpurity | ≤ 0.01 | — |
| Pbimpurity | ≤ 0.03 | — |
| Other (total)sum of other elements | ≤ 0.15 | — |
| Cu | balance | — |
BAg-8 Hard — frequently asked
What is BAg-8 Hard used for?
BAg-8 Hard is typically used for carbide tool tip brazing, vacuum furnace brazing and electronic and RF component assembly. In short: eutectic, single melting point; zinc-free vacuum brazing filler; 87 % IACS conductivity.
What is the yield strength of BAg-8 Hard?
BAg-8 Hard has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 97% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is BAg-8 Hard easy to machine?
Reasonably — machinability is rated good (65/100, better than 100% of precious metal grades). Soft and gummy: turning preforms requires sharp, high-rake tooling, high spindle speed and ample lubricant to prevent smearing and built-up edge.
Can BAg-8 Hard be welded?
Not readily — weldability is rated poor (28/100). This is a brazing filler metal. Furnace or vacuum braze at roughly 800–870 °C; the eutectic has no mushy range, so heat quickly and uniformly and avoid long soaks that soften the base metal.
What surface finishes work on BAg-8 Hard?
Pickle joints after brazing to remove flux residue. The copper-rich phase darkens in sulphide atmospheres, so plate cosmetic joints with nickel or rhodium.
Can BAg-8 Hard be formed, bent or molded?
Annealed material is ductile enough to draw to wire, roll to foil and stamp into rings and shims. After hard drawing, interanneal at about 600 °C with a rapid cool to restore ductility.
What is the maximum service temperature of BAg-8 Hard?
BAg-8 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 BAg-8 Annealed and BAg-8 Hard?
Annealed is the default condition — default stocked form: soft wire, rod or strip at 380 MPa tensile and 20% elongation, easy to bend into preformed rings and hand-feed, but too limp for automatic feeders. Hard: pick hard-drawn wire when an automatic feeder or stamping blank needs stiffness: 620 MPa tensile and 130 HB, with elongation dropping to 4% and formability limited. Yield strength is 160 MPa in Annealed versus 480 MPa in Hard.
Sources
- AWS A5.8/A5.8M Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- GB/T 10046 (2018)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- Silver brazing filler metal data (72Ag-28Cu eutectic) — Lucas-Milhaupt / Handy & Harman (2020)
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.