Aluminum 4004-H18
Temper
AA 4004 · UNS A94004 · EN AW-4004, AlSi10Mg1.5
H18 = strain hardened, full hard
Full-hard thin foil/strip supplied as-rolled without interanneal; maximum strength, minimum ductility.
Values for the H18 condition
Other 4004 tempers and conditions
4004 is listed in 7 conditions; see the grade overview at 4004.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
after vacuum brazing thermal cycle (~600 °C) | Condition of the solidified 4004 fillet/clad after the brazing cycle; fully annealed, coarse Si structure, use for joint-strength design. | 75 | 170 | 6 | 55 HB | 40 % IACS |
ODefault Annealed | Default supply condition for 4004 braze foil and roll-bonded clad brazing sheet; maximum formability before the brazing cycle. | 90 | 200 | 10 | 60 HB | 38 % IACS |
Strain hardened, quarter hard | Light cold work for slightly stiffer fin/clad strip that still needs to be corrugated. | 155 | 225 | 7 | 70 HB | 37 % IACS |
Strain hardened, half hard | Most common hard condition for 4004-clad brazing sheet supplied for fin forming and stamped plates. | 195 | 250 | 5 | 80 HB | 37 % IACS |
Strain hardened, three-quarter hard | Stiffer strip where fin collapse resistance during brazing matters more than bend ductility. | 225 | 270 | 4 | 88 HB | 37 % IACS |
H18This page Strain hardened, full hard | Full-hard thin foil/strip supplied as-rolled without interanneal; maximum strength, minimum ductility. | 255 | 290 | 3 | 95 HB | 37 % IACS |
Strain hardened, extra hard | Very thin heavily cold-rolled braze foil used as a free-standing interlayer shim in vacuum brazing. | 280 | 310 | 2 | 100 HB | 37 % IACS |
What is 4004-H18?
4004-H18 is 4004 in the H18 temper — full-hard thin foil/strip supplied as-rolled without interanneal; maximum strength, minimum ductility. 4004-H18 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi). 4004-H18 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). O is the default condition FabDigit quotes; H18 is available on request or by drawing note.
Limitations
- Hard to polish — 35/100, worse than 98% of aluminum grades
- Difficult to machine — 40/100, worse than 81% of aluminum grades
- Limited ductility — 3%, worse than 79% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
4004-H18 properties
Typical room-temperature values for 4004-H18; 19 are specific to this condition. Other listed values are 4004 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
4004-H18 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
4004-H18 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
4004-H18 is rated for continuous service to 120°C (248 °F). It conducts heat at 150 W/m·K (86.7 BTU/hr·ft·°F), better than 58% of aluminum grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
4004-H18 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of 4004-H18 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
4004-H18's machinability is fair (40/100, worse than 81% of aluminum grades); weldability fair (45/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4004-H18
Is 4004 easy to machine?
Rarely machined; when required use PCD or diamond-coated carbide, high speed and flood coolant because ~10 % primary/eutectic Si is very abrasive.
Can 4004 be welded?
Mainly used as a braze filler; GTAW/GMAW is possible but the 1–2 % Mg with 10 % Si makes the deposit hot-short and porosity-prone, so pre-clean and keep heat input low.
Can 4004 be formed, bent or molded?
Form in O or H12 temper — clad brazing sheet corrugates and stamps well, but bend radii must be generous in H16/H18 since the Si-rich layer cracks readily.
What surface finishes work on 4004?
Do not decorative-anodize (dark grey, blotchy); after brazing, the surface is normally left as-brazed, chromate-free conversion coated, or e-coated for corrosion protection.
4004 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 |
|---|---|---|
| Sisets the low melting range | 9 – 10.5 | 9.8 |
| Mgoxide getter for fluxless vacuum brazing | 1 – 2 | 1.5 |
| Fe | ≤ 0.8 | — |
| Cu | ≤ 0.25 | — |
| Mn | ≤ 0.1 | — |
| Zn | ≤ 0.2 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
4004-H18 — frequently asked
What is 4004-H18 used for?
4004-H18 is typically used for automotive radiator/HVAC brazing clad sheet, vacuum brazed heat exchangers and clad fin stock. In short: vacuum brazing clad layer; low melting Al-Si filler; not a structural mill product.
What is the yield strength of 4004-H18?
4004-H18 has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is 4004-H18 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of aluminum grades). Rarely machined; when required use PCD or diamond-coated carbide, high speed and flood coolant because ~10 % primary/eutectic Si is very abrasive.
Can 4004-H18 be welded?
With care — weldability is rated fair (45/100). Mainly used as a braze filler; GTAW/GMAW is possible but the 1–2 % Mg with 10 % Si makes the deposit hot-short and porosity-prone, so pre-clean and keep heat input low.
What surface finishes work on 4004-H18?
Do not decorative-anodize (dark grey, blotchy); after brazing, the surface is normally left as-brazed, chromate-free conversion coated, or e-coated for corrosion protection.
Can 4004-H18 be formed, bent or molded?
Form in O or H12 temper — clad brazing sheet corrugates and stamps well, but bend radii must be generous in H16/H18 since the Si-rich layer cracks readily.
What is the maximum service temperature of 4004-H18?
4004-H18 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4004-O and 4004-H19?
O is the default condition — default supply condition for 4004 braze foil and roll-bonded clad brazing sheet; maximum formability before the brazing cycle. H19: very thin heavily cold-rolled braze foil used as a free-standing interlayer shim in vacuum brazing. Yield strength is 90 MPa in O versus 280 MPa in H19.
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 (BAlSi-7) — AWS (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Aluminum Brazing) — ASM International (1993)
- Aluminium brazing sheet / cladding alloy data (4004, 4104, 4343) — Multiple rolling mills (2023)
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.