Aluminium alloy 4047 4047

Al-Si alloy, nominal composition Si 11.0 to 13.0, Fe 0.80 max, Cu 0.30 max, Mn 0.15 max, Mg 0.10 max, Zn 0.20 max, Al balance (wt%, US alloy 4047)

Also known as UNS A94047, EN name EN AW-4047A, AA 4047, ISO S Al 4047A, AMS 4185, OK Autrod 4047

4047 is an aluminium-silicon filler alloy with 11 to 13 % silicon, also written BAlSi-4 (brazing) and ER4047 (welding), UNS A94047.

8 sources · Updated 2026-10-26 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Brazing at low temperature

574 to 632 °C solidus to liquidus

Weight

2.65 g/cm3

Conduct current

41 % IACS

Tensile strength as welded

124 MPa

Recipe, share of the weight

  • Al not statedAluminium
  • Si not statedSilicon
  • Fe not statedIron
  • Cu not statedCopper
  • Zn not statedZinc
  • Mn not statedManganese
  • Mg not statedMagnesium

Best for

Brazing and welding filler for aluminium parts where a low melting range and reduced hot cracking matter (suppliers cite high fluidity and low shrinkage)

Weakest at

Low strength in the as-welded form (about 124 MPa tensile and 55 MPa yield, supplier data) and no sourced property data for brazed joints

Risk at a glance

  • People None found. Not classified hazardous; fumes need control
  • If it fails No data. No failure risks recorded
  • Corrosion No data. No corrosion data recorded

Quick facts: 4047

Key properties of 4047
PropertyValueBasis
Density2.65 to 2.66 g/cm³2 sourced values across conditions
Yield strength55 MPa1 sourced value
Tensile strength124 MPa1 sourced value
Melting point576 to 582 °C2 sourced values across conditions

What is the density of Aluminium alloy 4047?

Aluminium alloy 4047 has a density of 2.65 to 2.66 g/cm³. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the melting point of Aluminium alloy 4047?

Aluminium alloy 4047 has a melting point of 576 to 582 °C. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the yield strength of Aluminium alloy 4047?

Aluminium alloy 4047 has a yield strength of 55 MPa. The source and test conditions are listed in the properties table on this page.

What is the tensile strength of Aluminium alloy 4047?

Aluminium alloy 4047 has a tensile strength of 124 MPa. The source and test conditions are listed in the properties table on this page.

What are the other names and codes for Aluminium alloy 4047?

Aluminium alloy 4047 is also written as UNS A94047, EN name EN AW-4047A, AA 4047, ISO S Al 4047A, AMS 4185, OK Autrod 4047. Each code is printed in the source listed beside it in the designations table.

What is Aluminium alloy 4047 used for?

Uses recorded in the sources include Automotive radiators and battery cooling modules; Laser-welded covers for microwave integrated circuits, and leak-tight joints.

Why it exists

4047 is an aluminium-silicon filler with 11 to 13 % silicon. It was developed as a brazing alloy because its low melting range and narrow freezing range suit joining, and its extra silicon improves fluidity and reduces shrinkage. Supplier data give a density of 2.65 g/cm3, a solidus of 574 °C and a liquidus of 632 °C, and a brazing range of 582 to 604 °C. The sources read here cover its use for automotive radiators and battery cooling modules, and laser-welded covers for microwave circuits, but no flight record.

Where it's used

Automotive radiators and battery cooling modules

Eagle Alloys says 4047 is used for radiators and battery cooling modules, and that it is particularly useful in the automotive industry for parts and engine blocks.

Laser-welded covers for microwave circuits

Eagle Alloys lists laser-welded covers for microwave integrated circuits and leak-tight joints among its applications. The page gives no numbers for these uses.

Recipe

Al-Si alloy, nominal composition Si 11.0 to 13.0, Fe 0.80 max, Cu 0.30 max, Mn 0.15 max, Mg 0.10 max, Zn 0.20 max, Al balance (wt%, US alloy 4047)

4047 is a non-heat-treatable aluminium-silicon filler with 11 to 13 % silicon. It was developed as a brazing alloy (BAlSi-4) because of its low melting point and narrow freezing range (AlcoTec). It is supplied as wire, rod, sheet, pig, grains, shot and chips (AMS 4185 scope). The composition below is the specification range.

What 4047 is made of
IngredientShare of the weightWhat it does
Aluminium Al not stated The matrix of the alloy. Balance of the composition.
Silicon Si not stated The defining element. It gives the alloy its low melting range and high fluidity, and reduces shrinkage and hot cracking (AlcoTec, ESAB).
Iron Fe not stated An impurity limit in the specification, not a deliberate addition.
Copper Cu not stated A low-level impurity limit.
Zinc Zn not stated A low-level impurity limit.
Manganese Mn not stated A low-level impurity limit.
Magnesium Mg not stated A low-level impurity limit.

Weight shares are as printed in the sources.

What it can do

Brazing at low temperature

574 to 632 °C solidus to liquidus

measured

The supplier gives a solidus of 574 °C and a liquidus of 632 °C, with a brazing range of 582 to 604 °C.

Weight

2.65 g/cm3

measured

The supplier gives a density of 2.65 g/cm3. The AlcoTec sheet prints 0.096 lb/in3.

Conduct current

41 % IACS

measured

The AlcoTec sheet prints an electrical conductivity of 41 % IACS for the -O temper.

Tensile strength as welded

124 MPa

measured

The ESAB datasheet gives 124 MPa tensile and 55 MPa yield for as-welded wire weld metal, with 12 % elongation.

How it compares

The sources here give density, melting range and as-welded strength for 4047 only. They do not compare it numerically with other grades in this collection, so the comparison rows below show its own values.

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.

Benchmarks
Measurement404760617075-T6202450525XXX2195 (Al-Cu-Li)Al10502011201420172017A221923192618A30033103501950565083AlMg2AlMg36013606360826101AA7050AA8011Au-Al IMCsAl master alloys
Thermal behavior and safety
Melting range (eutectic point), 40471068 to 1080 °F3no data532 °Cno data607.2 to 649 °Cno data1020 degF660 °C645 to 657 °C540 °C535 °C510 °C510 °C543 °C543 to 643 °C549 °C655 °C655 °C575 to 630 °C565 to 640 °C570 °C605 to 650 °C590 to 645 °C579 °C600 °C575 °C1090 °F490 °C640 to 655 °Cno data880 °C
Melting range, 4047 (AlcoTec datasheet)1070 to 1080 °F4no data532 °Cno data607.2 to 649 °Cno data1020 degF660 °C645 to 657 °C540 °C535 °C510 °C510 °C543 °C543 to 643 °C549 °C655 °C655 °C575 to 630 °C565 to 640 °C570 °C605 to 650 °C590 to 645 °C579 °C600 °C575 °C1090 °F490 °C640 to 655 °Cno data880 °C
Physical and electrical
Density, 40472.65 g/cm³12.7 g/cm³2.8 Mg/m32.78 g/cc2.68 g/cc2.68 g/cm³0.096 lb/in32.7 g/cm³2.71 g/cm³2.82 g/cm³2.82 g/cm³2.79 g/cm³2.79 g/cm³2.84 g/cm³2.84 g/cm³2.76 g/cm³2.73 g/cm³2.73 g/cm³2.64 g/cm³2.64 g/cm³2.65 g/cm³2.69 g/cm³2.67 g/cm³2.71 g/cm³2700 kg/m32.7 g/cm³0.097 lb/cu.in2.83 g/cm³2.71 g/cm³no datano data
Density, 4047 (AlcoTec datasheet)0.096 lb/in322.7 g/cm³2.8 Mg/m32.78 g/cc2.68 g/cc2.68 g/cm³0.096 lb/in32.7 g/cm³2.71 g/cm³2.82 g/cm³2.82 g/cm³2.79 g/cm³2.79 g/cm³2.84 g/cm³2.84 g/cm³2.76 g/cm³2.73 g/cm³2.73 g/cm³2.64 g/cm³2.64 g/cm³2.65 g/cm³2.69 g/cm³2.67 g/cm³2.71 g/cm³2700 kg/m32.7 g/cm³0.097 lb/cu.in2.83 g/cm³2.71 g/cm³no datano data
Electrical conductivity, 4047 (-O temper)41 % IACS8no datano datano datano data29 % IACSno datano data58.4 % IACSno datano datano datano data17.4 x10^6 S/mno datano datano datano datano datano datano data39.4 % IACS20 to 23 m/(Ω·mm²)no datano data42 %IACS57 % IACS> 23 MS/m3.4×10^7 to 3.5×10^7 S/mno datano data
Temperature behavior
Solidus, 4047574 °C5no datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano data
Liquidus, 4047632 °C6no datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano data
Brazing temperature range, 4047582 to 604 °C7no datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano data
Other measurements
Yield strength, 4047 weld metal, as welded (OK Autrod 4047 wire)55 MPa9276 MPa503 MPa324 MPa13 ksi193 MPa74 ksi29 MPa> 85 MPa140 MPa> 400 MPa276 MPa276 MPa> 50 ksi70 MPa350 MPa50 MPa> 110 MPano datano data> 125 MPa> 120 MPa> 80 MPa350 MPa21 ksi> 255 MPa28000 psi> 414 MPano datano datano data
Tensile strength, 4047 weld metal, as welded (OK Autrod 4047 wire)124 MPa10310 MPa572 MPa469 MPa28 ksi228 MPa80 ksi88 MPa105 to 145 MPa300 MPa> 460 MPa427 MPa427 MPa> 62 ksi160 MPa420 MPa110 MPa> 140 MPa270 to 350 MPa300 MPa275 to 350 MPa190 to 230 MPa190 to 260 MPa410 MPa27 ksi> 300 MPa32000 psi> 483 MPa180 to 195 MPano datano data
Elongation, 4047 weld metal, as welded (OK Autrod 4047 wire)12 %1117 %11 %19 %25 %12 %8 %50 to 65 %4 to 8 %16 %> 6 %18 %18 %> 6 %12 %> 5 %25 %> 8 %> 2 %20 %> 12 %4 to 12 %> 12 %4 %8 %> 9 %> 8 %> 7 %> 1 %no datano data

Why choose it, and why not

Good for

  • Brazing and welding aluminium parts that need a low melting range and reduced hot cracking, such as automotive radiators and battery cooling modules.
  • Laser-welded covers and leak-tight joints in microwave circuit packages, as Eagle Alloys lists.

Watch out for

  • Low as-welded strength: about 124 MPa tensile and 55 MPa yield in the ESAB datasheet.
  • Corrosion is rated only by a letter scale (B general, A stress corrosion) with no test data.
  • Welding fumes can be harmful. The SDS warns against breathing them and lists fume constituents for the product family.
  • No flight, spacecraft or launch use of 4047 is confirmed by any source read here.

4047 is a practical, low-melting aluminium-silicon filler for brazing and welding, with supplier data on its melting range, density and as-welded strength. Its sources give no thermal, brazed-joint or space data, so those values are left as gaps.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Other names and standards

The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.

Other names and standards
SystemCodes
UNSA94047
EN nameEN AW-4047A (European (EAA) version, printed as Alloy 4047A EAA)
AA4047
ISOS Al 4047A (EN ISO 18273 filler designation)
AMS4185 (Filler metal, aluminum brazing, 12Si (4047))
Trade nameOK Autrod 4047

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Density, 4047Value printed on a supplier page, Physical propertiesform not statedtemperature not stated—
2Density, 4047 (AlcoTec datasheet)Value printed on a manufacturer weld datasheet, Typical Propertiesform not statedunit in source lbs./cu. in.—
3Melting range (eutectic point), 4047Range printed on a supplier page, Physical Propertiesform not statedcondition in source printed as eutectic point—
4Melting range, 4047 (AlcoTec datasheet)Range printed on a manufacturer weld datasheet, Typical Propertiesform not stated—
5Solidus, 4047Value printed on a supplier page, Physical Propertiesform not statedunit in source printed as 1065 °F (574 °C)—
6Liquidus, 4047Value printed on a supplier page, Physical Propertiesform not statedunit in source printed as 1170 °F (632 °C)—
7Brazing temperature range, 4047Range printed on a supplier page, Physical Propertiesform not statedunit in source printed as 1080 to 1120 °F (582 to 604 °C)—
8Electrical conductivity, 4047 (-O temper)Value printed on a manufacturer weld datasheet, Typical Propertiestemper -O as printed on the sheetform not stated—
9Yield strength, 4047 weld metal, as welded (OK Autrod 4047 wire)Value printed on a manufacturer wire datasheet, Typical Tensile Propertiesproduct weld metal from ER4047 wire (ESAB OK Autrod 4047)temper as welded, no heat treatmentbasis typical value printed by the manufacturer—
10Tensile strength, 4047 weld metal, as welded (OK Autrod 4047 wire)Value printed on a manufacturer wire datasheet, Typical Tensile Propertiesproduct weld metal from ER4047 wire (ESAB OK Autrod 4047)temper as welded, no heat treatmentbasis typical value printed by the manufacturer—
11Elongation, 4047 weld metal, as welded (OK Autrod 4047 wire)Value printed on a manufacturer wire datasheet, Typical Tensile Propertiesproduct weld metal from ER4047 wire (ESAB OK Autrod 4047)temper as welded, no heat treatmentgauge length not stated—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
General and stress corrosion, qualitative rating (AlcoTec datasheet) not rated The AlcoTec datasheet rates 4047 B for general corrosion and A for stress corrosion, on a scale the sheet does not define.1
Corrosion details
#EnvironmentDetailsTest conditions
1 General and stress corrosion, qualitative rating (AlcoTec datasheet) The sheet prints 'Resistance to corrosion: B (Gen) A (SCC)'. The rating key is not printed, and no exposure environment, test or result is given for 4047. basis letter rating printed on a manufacturer datasheettest none stated

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The Airgas SDS for a filler family that includes ER4047 says the product is not classified as hazardous. It also warns about welding fumes. No health data specific to 4047 were found.

The product
The SDS says the product is not classified as hazardous under GHS and needs no label symbol or signal word.
Fumes
The same SDS warns that welding fumes and gases may be dangerous to health and that fumes depend on the base metal, its coating and the process.

If it fails

The sources give no failure-mode data for brazed or welded joints.

Strength
As-welded wire weld metal is printed at 55 MPa yield and 124 MPa tensile, with 12 % elongation (ESAB).
Corrosion
The AlcoTec sheet rates general corrosion B and stress corrosion A on a letter scale it does not define. No test result was found.

Handling and storage

Ventilation
Use adequate ventilation and personal protective equipment when welding or brazing, as the SDS says.
Form
State the form (wire, sheet, grains) when comparing values, because the AMS 4185 scope covers several forms.

Test details
The original wording and numbers from the sources, for readers who want them.

Handling and storage

  • Avoid breathing welding fumes and gases. The SDS says to use adequate ventilation and appropriate personal protective equipment.
  • State the form of the filler. The AMS 4185 scope covers wire, sheet, pig, grains, shot and chips, and the properties above are for wire weld metal.

Supply and geography

How common the raw materials are and where they come from.

Primary aluminium smelter production, 2025 estimate (world)

Top producers (2025)
China 60.8%, India 5.7%, Russia 5.3%, Canada 4.5%, United Arab Emirates 3.6%
Recycling
USGS: in 2025 about 3.6 million tons of aluminum were recovered from purchased scrap in the United States, about 56 % from new scrap and 44 % from old scrap. Old-scrap recovery was equivalent to about 28 % of apparent consumption.
Substitutes
USGS: composites can substitute for aluminum in aircraft fuselages and wings. Copper can replace aluminum in electrical and heat-exchange applications.