Aluminum 4104
AA 4104 · EN AW-4104, AlSi10MgBi
4104 is a bismuth-modified Al-10Si-Mg brazing alloy (EN AW-4104, AlSi10MgBi) supplied as brazing sheet clad layers, foil and preforms in O, H14, H18, F and as-brazed condition.
Reference datasheet — 4104 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.
Values for the O condition
4104 tempers and conditions
4104 is supplied in 5 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Standard supply condition for brazing-sheet cladding, brazing foil and coiled filler wire where maximum formability is needed before brazing. | 70 | 165 | 18 | 45 HB | 40 % IACS |
solidified joint fillet after CAB/vacuum brazing | Condition of the filler metal in a finished joint; used for joint-strength estimation rather than for stock purchasing. | 75 | 145 | 3 | 55 HB | 37 % IACS |
As fabricated | As-fabricated cast or extruded stock for cut preforms, rings and paste/powder feedstock, where mechanical properties are not specified. | 80 | 150 | 6 | 50 HB | 40 % IACS |
Strain hardened, half hard | Half-hard foil/strip and straightened filler rod where handling stiffness and cut-length straightness matter more than bendability. | 170 | 200 | 5 | 60 HB | 39 % IACS |
Strain hardened, full hard | Fully cold-worked thin foil and drawn wire, used where a stiff, dimensionally stable preform or wire feed is required. | 220 | 240 | 2 | 72 HB | 39 % IACS |
What is 4104?
4104 is a bismuth-modified Al-10Si-Mg brazing alloy (EN AW-4104, AlSi10MgBi) supplied as brazing sheet clad layers, foil and preforms in O, H14, H18, F and as-brazed condition. The Mg and Bi additions let it wet and flow during controlled-atmosphere brazing (CAB) without corrosive flux residue, which improves joint reliability in automotive HVAC and flux-free lines. Reference values are 165 MPa tensile, 70 MPa yield, 18% elongation, 45 HB, 160 W/m·K and 40% IACS, but it is a filler rather than a structural base metal, with machinability 28 and formability 60. Where fluxed furnace or torch brazing is used instead, 4147 is the equivalent filler. 4104 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 559°C (1,038 °F). 4104 has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 92% of aluminum grades. Elongation at break is 18% and the elastic modulus is 72 GPa (10.4 Msi).
What is 4104 used for?
- CAB (controlled atmosphere brazing) heat exchangers
- automotive HVAC brazing
- flux-free brazing processes
Advantages
- Ductile — tolerates forming and impact — 18%, better than 86% of aluminum grades
- Forms and bends easily — 60/100, better than 77% of aluminum grades
- Conducts heat well — 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades
Limitations
- Hard to polish — 30/100, worse than 100% of aluminum grades
- Difficult to machine — 28/100, worse than 94% of aluminum grades
- Low strength — 70 MPa (10.2 ksi), worse than 92% of aluminum grades
4104 properties
Typical room-temperature values for 4104-O; bars are the position among aluminum grades.
Physical3
4104 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 559°C (1,038 °F).
Mechanical10
4104 has a yield strength of 70 MPa (10.2 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 92% of aluminum grades. Elongation at break is 18% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal6
4104 is rated for continuous service to 150°C (302 °F). It conducts heat at 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades. Thermal expansion is 20 µm/m·K (11.1 µin/in·°F).
Electrical3
4104 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 4104 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability8
4104's machinability is poor (28/100, worse than 94% of aluminum grades); weldability fair (35/100); formability good (60/100).
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. 4104 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 4104
Is 4104 easy to machine?
Rarely machined; if trimming preforms use sharp PCD/carbide tooling — the primary silicon is abrasive and the soft matrix loads flutes.
Can 4104 be welded?
Not a base metal for welding; it is itself a filler. Fusion welding of the clad layer produces brittle, crack-prone Si-rich beads.
Can 4104 be formed, bent or molded?
In O temper the clad layer follows the core sheet through deep drawing and fin rolling; avoid heavy cold work in H18 which cracks on tight bends.
4104 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 |
|---|---|---|
| Siprimary melting-point depressant | 9 – 10.5 | 9.8 |
| Mgoxide-disrupting getter for vacuum/CAB brazing | 1 – 2 | 1.5 |
| Bilowers surface tension, improves fillet flow | 0.02 – 0.2 | 0.1 |
| Fe | ≤ 0.8 | |
| Cu | ≤ 0.25 | |
| Mn | ≤ 0.1 | |
| Zn | ≤ 0.2 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 4104?
Do not use decorative anodizing (dark, mottled from Si); chromate-free conversion coating or e-coat is normal for brazed heat-exchanger assemblies.
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).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 4104 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- AW-4104AlSi10MgBi
- Also called
- BAlSi-11
How much does 4104 cost?
4104 is a premium-cost aluminum ($$$), cheaper than about 51% 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.
4104 — frequently asked
What is 4104 used for?
4104 is typically used for CAB (controlled atmosphere brazing) heat exchangers, automotive HVAC brazing and flux-free brazing processes. In short: flux-free CAB brazing filler; bismuth-modified wetting; filler, not structural metal.
What is the yield strength of 4104?
4104 has a typical yield strength of 70 MPa (10.2 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 92% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is 4104 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 94% of aluminum grades). Rarely machined; if trimming preforms use sharp PCD/carbide tooling — the primary silicon is abrasive and the soft matrix loads flutes.
Can 4104 be welded?
With care — weldability is rated fair (35/100). Not a base metal for welding; it is itself a filler. Fusion welding of the clad layer produces brittle, crack-prone Si-rich beads.
What surface finishes work on 4104?
Do not use decorative anodizing (dark, mottled from Si); chromate-free conversion coating or e-coat is normal for brazed heat-exchanger assemblies.
Can 4104 be formed, bent or molded?
In O temper the clad layer follows the core sheet through deep drawing and fin rolling; avoid heavy cold work in H18 which cracks on tight bends.
What is the maximum service temperature of 4104?
4104 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 4104-O and 4104-H18?
O is the default condition — standard supply condition for brazing-sheet cladding, brazing foil and coiled filler wire where maximum formability is needed before brazing. H18: fully cold-worked thin foil and drawn wire, used where a stiff, dimensionally stable preform or wire feed is required. Yield strength is 70 MPa in O versus 220 MPa in H18.
How much does 4104 cost?
4104 is a premium-cost aluminum ($$$), cheaper than about 51% 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
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- AWS A5.8/A5.8M Specification for Filler Metals for Brazing and Braze Welding — AWS (2019)
- EN 573-3 Aluminium and aluminium alloys — Chemical composition — CEN (2019)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 6: Welding, Brazing and Soldering (Aluminium brazing) — ASM International (1993)
- Aluminium brazing sheet product literature (clad alloy data) — Aluminium brazing-sheet producers (2022)
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.