Aluminum 4104-O (Annealed)
Temper · default condition
AA 4104 · EN AW-4104, AlSi10MgBi
Standard supply condition for brazing-sheet cladding, brazing foil and coiled filler wire where maximum formability is needed before brazing.
Values for the O condition
Other 4104 tempers and conditions
4104 is listed in 5 conditions; see the grade overview at 4104.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefaultThis page 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-O?
4104-O is 4104 in the O temper — standard supply condition for brazing-sheet cladding, brazing foil and coiled filler wire where maximum formability is needed before brazing. 4104-O 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). 4104-O 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).
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-O properties
Typical room-temperature values for 4104-O; 10 are specific to this condition. Other listed values are 4104 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
4104-O 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-O 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-O 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-O 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-O 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-O'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. Confirm any required mill or lot documentation when quoting.
Working with 4104-O
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.
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.
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 | — |
4104-O — frequently asked
What is 4104-O used for?
4104-O 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-O?
4104-O 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-O 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-O 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-O?
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-O 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-O?
4104-O 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.