Aluminum 4047
AA 4047 · UNS A94047 · EN AlSi12, AW-4047
4047 (AlSi12, UNS A94047, EN AW-4047) is a near-eutectic Al-Si alloy with about 12% silicon supplied as brazing sheet cladding, brazing foil and GTAW/GMAW filler wire rather than as a structural product.
Values for the F condition
4047 tempers and conditions
4047 is supplied in 3 conditions, soft to hard. F is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick when maximum ductility is needed for coiling, stamping of brazing foil, or roll-bonded clad sheet before the braze cycle. | 55 | 130 | 22 | 42 HB | 40 % IACS |
FDefault As fabricated | Default stocked condition for 4047 welding wire, brazing rod, foil and brazing-sheet cladding — no controlled mechanical properties, chosen for melting behaviour rather than strength. | 70 | 170 | 18 | 52 HB | 39 % IACS |
As-welded deposit | Properties of the solidified 4047 deposit itself — reference this when qualifying joint strength or braze-fillet behaviour. | 80 | 180 | 10 | 55 HB | 37 % IACS |
What is 4047?
4047 (AlSi12, UNS A94047, EN AW-4047) is a near-eutectic Al-Si alloy with about 12% silicon supplied as brazing sheet cladding, brazing foil and GTAW/GMAW filler wire rather than as a structural product. It is specified for its fluidity and low hot-cracking tendency when joining aluminum castings and heat exchanger assemblies, with typical values of 70 MPa yield, 170 MPa tensile, 18% elongation, 52 HB and 155 W/m·K. It is not heat treatable, is abrasive to cut (machinability 40), anodizes dark and blotchy, and is limited to about 150 °C in service. 4043 is the alternative where slightly lower silicon and better weld appearance are wanted. 4047 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 577°C (1,071 °F). 4047 has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 92% of aluminum grades. Elongation at break is 18% and the elastic modulus is 71 GPa (10.3 Msi).
What is 4047 used for?
- Brazing filler
- Heat exchangers
- Brazing sheet cladding layers
- TIG/MIG filler wire for 3xx aluminum castings
- Vacuum and CAB brazed cold plates
- Radiator and condenser assemblies
- Repair welding of cast housings
Advantages
- Readily welded — 92/100, better than 95% of aluminum grades
- Ductile — tolerates forming and impact — 18%, better than 86% of aluminum grades
Limitations
- Low strength — 70 MPa (10.2 ksi), worse than 92% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Difficult to machine — 40/100, worse than 81% of aluminum grades
4047 properties
Typical room-temperature values for 4047-F; bars are the position among aluminum grades.
Physical3
4047 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 577°C (1,071 °F).
Mechanical11
4047 has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 92% of aluminum grades. Elongation at break is 18% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
4047 is rated for continuous service to 150°C (302 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 20 µm/m·K (11.1 µin/in·°F).
Electrical3
4047 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of 4047 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability8
4047's machinability is fair (40/100, worse than 81% of aluminum grades); weldability excellent (92/100); formability fair (35/100).
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 aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 4047 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 4047
Is 4047 easy to machine?
Abrasive high-Si microstructure — use polished-flute carbide or PCD tooling, high speed, low feed and flood coolant; expect short tool life vs 6061.
Can 4047 be welded?
This is the filler alloy itself: excellent fluidity and the lowest hot-cracking tendency of the Al-Si fillers, ideal for GTAW/GMAW of 3xx castings and Si-tolerant wrought alloys, but avoid on Mg-bearing 5000-series base metals (brittle Mg2Si) and where post-weld anodizing colour matters.
Can 4047 be formed, bent or molded?
Very high casting/brazing fluidity with minimal shrinkage; wrought forming is limited — cold bending of wire/foil only, no heat-treat strengthening available.
Manufacturability
The process limits FabDigit applies to 4047. Every 4047 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Good40 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Good35 / 100 |
|---|---|
| Weldability | Excellent92 / 100 |
4047 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 |
|---|---|---|
| Sinear-eutectic silicon content | 11 – 13 | 12 |
| Fe0.6 max for EN AW-4047A | ≤ 0.8 | |
| Cu | ≤ 0.3 | |
| Mn | ≤ 0.15 | |
| Mg0.10 max; some vacuum-braze variants restrict further | ≤ 0.1 | |
| Zn | ≤ 0.2 | |
| Tispecified for 4047A; not limited in AA 4047 | ≤ 0.15 | |
| Bewelding-consumable restriction (AWS A5.10) | ≤ 8×10⁻⁴ | |
| Others (each)total 0.15 max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 4047?
Anodizes dark and blotchy; prefer chromate/chemical conversion coating, paint, or leave as-brazed; mechanical polishing pulls out Si particles.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 4047 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 4047 cost?
4047 is a standard-cost aluminum ($$), cheaper than about 62% 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.
4047 — frequently asked
What is 4047 used for?
4047 is typically used for brazing filler, heat exchangers, brazing sheet cladding layers, TIG/MIG filler wire for 3xx aluminum castings, vacuum and CAB brazed cold plates and radiator and condenser assemblies. In short: aluminum brazing filler (~12% Si); excellent fluidity.
What is the yield strength of 4047?
4047 has a typical yield strength of 70 MPa (10.2 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 92% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is 4047 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of aluminum grades). Abrasive high-Si microstructure — use polished-flute carbide or PCD tooling, high speed, low feed and flood coolant; expect short tool life vs 6061.
Can 4047 be welded?
Yes — weldability is rated excellent (92/100). This is the filler alloy itself: excellent fluidity and the lowest hot-cracking tendency of the Al-Si fillers, ideal for GTAW/GMAW of 3xx castings and Si-tolerant wrought alloys, but avoid on Mg-bearing 5000-series base metals (brittle Mg2Si) and where post-weld anodizing colour matters.
What surface finishes work on 4047?
Anodizes dark and blotchy; prefer chromate/chemical conversion coating, paint, or leave as-brazed; mechanical polishing pulls out Si particles.
Can 4047 be formed, bent or molded?
Very high casting/brazing fluidity with minimal shrinkage; wrought forming is limited — cold bending of wire/foil only, no heat-treat strengthening available.
What is the maximum service temperature of 4047?
4047 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4047-F and 4047-O?
F is the default condition — default stocked condition for 4047 welding wire, brazing rod, foil and brazing-sheet cladding — no controlled mechanical properties, chosen for melting behaviour rather than strength. O: pick when maximum ductility is needed for coiling, stamping of brazing foil, or roll-bonded clad sheet before the braze cycle. Yield strength is 70 MPa in F versus 55 MPa in O.
How much does 4047 cost?
4047 is a standard-cost aluminum ($$), cheaper than about 62% 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.
Can FabDigit make parts in 4047?
Yes — 4047 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- AWS A5.10/A5.10M — Bare Aluminum and Aluminum-Alloy Welding Electrodes and Rods — AWS (2021)
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- EN ISO 18273 — Welding consumables, wire electrodes and rods for aluminium and aluminium alloys (S Al 4047 / AlSi12) — ISO (2015)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B / Vol. 6 — Corrosion and Welding, Brazing and Soldering — ASM International (1993)
- Aluminium filler metal 4047 / AlSi12 datasheets — Various filler-metal producers (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.