Precious Metal BAg-28 AS-BRAZED
Heat-treated state
UNS P07401
Use when rating joint performance: the thin solidified seam is constrained by the base metal, so measured lap shear far exceeds the 380 MPa, 20% bulk filler values; 200 °C service limit.
Values for the AS-BRAZED condition
What is BAg-28 AS-BRAZED?
BAg-28 AS-BRAZED is BAg-28 heat treated to AS-BRAZED — use when rating joint performance: the thin solidified seam is constrained by the base metal, so measured lap shear far exceeds the 380 MPa, 20% bulk filler values; 200 °C service limit. BAg-28 AS-BRAZED has a yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades. Elongation at break is 20% and the elastic modulus is 90 GPa (13.1 Msi). BAg-28 AS-BRAZED has a density of 9.3 g/cm³ (0.336 lb/in³), lighter than 85% of precious metal grades. It melts at 649°C (1,200 °F).
Advantages
- Low embodied carbon — 50 kg CO₂/kg, better than 90% of precious metal grades
Limitations
- Needs corrosion protection — 55/100, worse than 94% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Limited ductility — 20%, worse than 77% of precious metal grades
- Hard to polish — 70/100, worse than 76% of precious metal grades
BAg-28 AS-BRAZED properties
Typical room-temperature values for BAg-28 AS-BRAZED; 5 are specific to this condition. Other listed values are BAg-28 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BAg-28 AS-BRAZED has a density of 9.3 g/cm³ (0.336 lb/in³), lighter than 85% of precious metal grades. It melts at 649°C (1,200 °F).
Mechanical9
BAg-28 AS-BRAZED has a yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades. Elongation at break is 20% and the elastic modulus is 90 GPa (13.1 Msi).
Thermal5
BAg-28 AS-BRAZED is rated for continuous service to 200°C (392 °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 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BAg-28 AS-BRAZED conducts electricity at 18 % IACS, worse than 54% of precious metal grades.
Chemical & Environmental2
Corrosion resistance is good (55/100), worse than 94% of precious metal grades.
Sustainability3
Producing a kilogram of BAg-28 AS-BRAZED takes about 700 MJ of energy and emits 50 kg of CO₂ — less than 90% of precious metal grades. Typical recycled content is 40%.
Manufacturability4
BAg-28 AS-BRAZED's machinability is fair (45/100, better than 59% of precious metal grades); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BAg-28 AS-BRAZED
Is BAg-28 easy to machine?
The filler is rarely machined on its own. When a brazed joint is cut, the fillet is soft and tends to smear and load the tool, so use sharp, keen-edged tooling and low feed.
Can BAg-28 be welded?
This is a brazing filler metal, not a welding consumable: apply by torch, induction or furnace brazing at 710–843 °C with an AWS FB3-A/FB3-C flux. The relatively wide melting range calls for rapid, uniform heating to prevent liquation and segregation.
Can BAg-28 be formed, bent or molded?
Annealed material is ductile and can be drawn to wire, rolled to strip and stamped into rings, washers and other preforms. Use intermediate annealing after heavy cold work.
What surface finishes work on BAg-28?
Remove all residual borax-type flux after brazing with hot water or an acid pickle. Fillets can be polished and nickel- or gold-plated; zinc-bearing joints should not see prolonged exposure to ammonia or sulphur-bearing environments.
BAg-28 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 |
|---|---|---|
| Ag | 39 – 41 | 40 |
| Cu | 29 – 31 | 30 |
| Snreplaces Cd; lowers liquidus and improves wetting | 1.5 – 2.5 | 2 |
| CdCd-free grade; controlled as an impurity | ≤ 0.01 | 0 |
| Other (total)sum of other impurities | ≤ 0.15 | |
| Zn | balance |
BAg-28 AS-BRAZED — frequently asked
What is BAg-28 AS-BRAZED used for?
BAg-28 AS-BRAZED is typically used for general fabrication brazing, plumbing and HVAC fittings and tool and die work. In short: cadmium-free BAg-2 replacement; wide melting range; gap-tolerant general filler.
What is the yield strength of BAg-28 AS-BRAZED?
BAg-28 AS-BRAZED has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 380 MPa (55.1 ksi) — stronger than 51% of precious metal grades.
Is BAg-28 AS-BRAZED easy to machine?
Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). The filler is rarely machined on its own. When a brazed joint is cut, the fillet is soft and tends to smear and load the tool, so use sharp, keen-edged tooling and low feed.
Can BAg-28 AS-BRAZED be welded?
This is a brazing filler metal, not a welding consumable: apply by torch, induction or furnace brazing at 710–843 °C with an AWS FB3-A/FB3-C flux. The relatively wide melting range calls for rapid, uniform heating to prevent liquation and segregation.
What surface finishes work on BAg-28 AS-BRAZED?
Remove all residual borax-type flux after brazing with hot water or an acid pickle. Fillets can be polished and nickel- or gold-plated; zinc-bearing joints should not see prolonged exposure to ammonia or sulphur-bearing environments.
Can BAg-28 AS-BRAZED be formed, bent or molded?
Annealed material is ductile and can be drawn to wire, rolled to strip and stamped into rings, washers and other preforms. Use intermediate annealing after heavy cold work.
What is the maximum service temperature of BAg-28 AS-BRAZED?
BAg-28 AS-BRAZED 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.
Sources
- AWS A5.8M/A5.8 Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- Brazing Handbook, 5th ed. — American Welding Society (2007)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
- Cadmium-free silver brazing alloy datasheets (40% Ag class) — Lucas-Milhaupt / Harris Products (2023)
- GB/T 10046 (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.