Precious Metal BAg-28
UNS P07401
BAg-28 is a cadmium-free silver-based brazing filler metal of the AWS BAg family (UNS P07401), developed as a replacement for cadmium-bearing BAg-2 with a comparable broad melting range and flow behaviour.
Reference datasheet — BAg-28 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.
BAg-28 tempers and conditions
BAg-28 is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BAg-28 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ANN-WIREDefault | Annealed wire / rod | Supply form |
FC-ROD | Flux-coated rod | Supply form |
STRIP | Strip / preform | Supply form |
PASTE | Powder / paste | Printing process |
What is BAg-28?
BAg-28 is a cadmium-free silver-based brazing filler metal of the AWS BAg family (UNS P07401), developed as a replacement for cadmium-bearing BAg-2 with a comparable broad melting range and flow behaviour. Engineers select it for general fabrication brazing where a wide working range helps bridge loose or variable joint gaps, and it is supplied as annealed wire, flux-coated rod, strip and paste. As-brazed joints show about 420 MPa tensile strength with 28 % elongation. The wide melting range requires fast, even heating to avoid liquation, and zinc-bearing fillets should not be left in ammonia or sulphur-bearing atmospheres. BAg-28 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). BAg-28 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 51% of precious metal grades. Elongation at break is 28% and the elastic modulus is 90 GPa (13.1 Msi).
What is BAg-28 used for?
- general fabrication brazing
- plumbing and HVAC fittings
- tool and die work
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
- Hard to polish — 70/100, worse than 76% of precious metal grades
BAg-28 properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
BAg-28 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 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 51% of precious metal grades. Elongation at break is 28% and the elastic modulus is 90 GPa (13.1 Msi).
Thermal5
BAg-28 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 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 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's machinability is fair (45/100, better than 59% of precious metal grades); 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. BAg-28 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAg-28
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.
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 |
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.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAg-28 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P07401
- Also called
- AWS BAg-28
How much does BAg-28 cost?
BAg-28 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAg-28 — frequently asked
What is BAg-28 used for?
BAg-28 is typically used for general fabrication brazing, plumbing and HVAC fittings and tool and die work. In short: cadmium-free BAg-2 replacement; wide melting range; gap-tolerant general filler.
What is the yield strength of BAg-28?
BAg-28 has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 51% of precious metal grades.
Is BAg-28 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). The filler is rarely machined on its own. When a brazed joint is cut, the fillet is soft and tends to smear and load the tool, so use sharp, keen-edged tooling and low feed.
Can BAg-28 be welded?
This is a brazing filler metal, not a welding consumable: apply by torch, induction or furnace brazing at 710–843 °C with an AWS FB3-A/FB3-C flux. The relatively wide melting range calls for rapid, uniform heating to prevent liquation and segregation.
What surface finishes work on BAg-28?
Remove all residual borax-type flux after brazing with hot water or an acid pickle. Fillets can be polished and nickel- or gold-plated; zinc-bearing joints should not see prolonged exposure to ammonia or sulphur-bearing environments.
Can BAg-28 be formed, bent or molded?
Annealed material is ductile and can be drawn to wire, rolled to strip and stamped into rings, washers and other preforms. Use intermediate annealing after heavy cold work.
What is the maximum service temperature of BAg-28?
BAg-28 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAg-28 cost?
BAg-28 is a high-cost precious metal ($$$$), 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)
- 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; 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.