Precious Metal BAg-37
UNS P07253
BAg-37 (UNS P07253) is a lower-silver, cadmium-free Ag-Cu-Zn brazing filler for general-purpose work where the full silver content of the richer grades is not required.
Reference datasheet — BAg-37 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-37 tempers and conditions
BAg-37 is supplied in one standard condition, AS-BRAZED.
Supply forms, finishes and certifications
Ways BAg-37 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FC-ROD | Flux-coated rod | Supply form |
POWDER-PASTE | Powder / Paste | Supply form |
RING | Ring / Preform | Supply form |
STRIP | Strip / Foil | Supply form |
WIREDefault | Wire / Rod | Supply form |
WIRE-HH | Wire | Supply form |
What is BAg-37?
BAg-37 (UNS P07253) is a lower-silver, cadmium-free Ag-Cu-Zn brazing filler for general-purpose work where the full silver content of the richer grades is not required. It provides an economical, health-safe option for steel and brass fabrication and is stocked as wire, hard-drawn wire, strip, rings, flux-coated rod, powder and paste, with about 400 MPa tensile and 25% elongation as brazed. Brazing runs at 810-860 °C with AWS FB3-A flux, hotter than the 50-65% silver grades, so thin sections need care; BAg-6 is the step up for lower brazing temperature and more ductility. BAg-37 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 96% of precious metal grades. It melts at 700°C (1,292 °F). BAg-37 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 67% of precious metal grades. Elongation at break is 25% and the elastic modulus is 90 GPa (13.1 Msi).
What is BAg-37 used for?
- cost-sensitive general brazing
- steel and brass fabrication
- cadmium-restricted operations
Advantages
- Low embodied carbon — 30 kg CO₂/kg, better than 98% of precious metal grades
- Lightweight — 8.7 g/cm³ (0.314 lb/in³), better than 96% of precious metal grades
Limitations
- Needs corrosion protection — 55/100, worse than 94% of precious metal grades
- Hard to polish — 60/100, 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
- Limited formability — 70/100, worse than 78% of precious metal grades
BAg-37 properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
BAg-37 has a density of 8.7 g/cm³ (0.314 lb/in³), lighter than 96% of precious metal grades. It melts at 700°C (1,292 °F).
Mechanical10
BAg-37 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 67% of precious metal grades. Elongation at break is 25% and the elastic modulus is 90 GPa (13.1 Msi).
Thermal6
BAg-37 is rated for continuous service to 200°C (392 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), better than 55% of precious metal grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
BAg-37 conducts electricity at 19 % IACS, worse than 51% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 94% of precious metal grades.
Sustainability4
Producing a kilogram of BAg-37 takes about 440 MJ of energy and emits 30 kg of CO₂ — less than 97% of precious metal grades. Typical recycled content is 40%.
Manufacturability7
BAg-37's machinability is fair (50/100, better than 74% of precious metal grades); weldability poor (20/100); formability very good (70/100).
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-37 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAg-37
Is BAg-37 easy to machine?
The filler itself is seldom machined. For cutting to length or shearing use sharp edges and low speeds, as the alloy is tough and smears onto tooling.
Can BAg-37 be welded?
Used as a brazing filler, not for fusion welding. Braze at 810-860 °C with an AWS FB3-A borax-fluoride flux, heating quickly and holding briefly to reduce zinc evaporation.
Can BAg-37 be formed, bent or molded?
Annealed material can be drawn to wire, rolled to strip and stamped into brazing rings. Intermediate anneal at about 600 °C when cold reduction is high.
BAg-37 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 / UNS P07253 | 24 – 26 | 25 |
| Cu | 39 – 41 | 40 |
| Cdcadmium-free grade; impurity maximum | ≤ 0.01 | 0 |
| Other (total)total of other elements | ≤ 0.15 | |
| Zn | balance |
What surface finishes work on BAg-37?
Residual flux must be removed completely after brazing with hot water or dilute acid, otherwise the residue corrodes the joint. Joints can be nickel or tin plated; polished seams are yellow-white and will not color-match stainless steel.
Equivalent designations
Standards and trade names that resolve to Precious Metal BAg-37 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- P07253
How much does BAg-37 cost?
BAg-37 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAg-37 — frequently asked
What is BAg-37 used for?
BAg-37 is typically used for cost-sensitive general brazing, steel and brass fabrication and cadmium-restricted operations. In short: economical cadmium-free BAg; general-purpose steel and brass; cadmium-restricted shops.
What is the yield strength of BAg-37?
BAg-37 has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 67% of precious metal grades.
Is BAg-37 easy to machine?
Reasonably — machinability is rated fair (50/100, better than 74% of precious metal grades). The filler itself is seldom machined. For cutting to length or shearing use sharp edges and low speeds, as the alloy is tough and smears onto tooling.
Can BAg-37 be welded?
Not readily — weldability is rated poor (20/100). Used as a brazing filler, not for fusion welding. Braze at 810-860 °C with an AWS FB3-A borax-fluoride flux, heating quickly and holding briefly to reduce zinc evaporation.
What surface finishes work on BAg-37?
Residual flux must be removed completely after brazing with hot water or dilute acid, otherwise the residue corrodes the joint. Joints can be nickel or tin plated; polished seams are yellow-white and will not color-match stainless steel.
Can BAg-37 be formed, bent or molded?
Annealed material can be drawn to wire, rolled to strip and stamped into brazing rings. Intermediate anneal at about 600 °C when cold reduction is high.
What is the maximum service temperature of BAg-37?
BAg-37 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does BAg-37 cost?
BAg-37 is a high-cost precious metal ($$$$), 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 — AWS (2019)
- GB/T 10046 (2018)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering — ASM International (1993)
- Cadmium-free silver brazing alloy (25% Ag) technical data — Lucas-Milhaupt / / (2023)
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.