Aluminum ER4009
ASTM AWS A5.10 ER4009
ER4009 is an Al-Si-Mg filler under AWS A5.10 with a chemistry matched to C355/A356/A357 castings, so the deposit responds to solution treatment and ageing like the parent metal.
Reference datasheet — ER4009 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 AW condition
ER4009 tempers and conditions
ER4009 is supplied in 4 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AWDefault As-welded deposit | Default condition for field or in-service repair of castings where no furnace cycle is possible; moderate strength, low ductility. | 125 | 200 | 3 | 60 HB | 37 % IACS |
As fabricated | Pick this for the physical wire or rod itself (spool feedability, straightness, cut-length stiffness), not for joint design. | 150 | 215 | 6 | 65 HB | 38 % IACS |
Cooled from hot working and artificially aged | Use when the component cannot be re-solutionised (distortion/quench risk) but a low-temperature age (~155–170 °C) can recover part of the strength. | 170 | 235 | 2.5 | 72 HB | 39 % IACS |
Solution heat treated and artificially aged | The reason ER4009 exists — full C355-T6 cycle on the repaired casting gives weld metal strength close to the parent material. | 215 | 290 | 3 | 88 HB | 39 % IACS |
What is ER4009?
ER4009 is an Al-Si-Mg filler under AWS A5.10 with a chemistry matched to C355/A356/A357 castings, so the deposit responds to solution treatment and ageing like the parent metal. Engineers select it for welding and repairing heat-treatable aluminum castings, and it is supplied as drawn wire and cut rod with F, AW, T5 and T6 conditions on file. As-welded values are about 125 MPa yield and 200 MPa tensile at 3 % elongation, so ductility is low and a full post-weld T6 is normally planned; maximum service temperature is about 150 °C. ER4010 or ER4043 are the alternatives when the joint will not be re-heat-treated. ER4009 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 546°C (1,015 °F). ER4009 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
What is ER4009 used for?
- A356/A357 casting repair
- automotive cast wheel welds
- cast housing repair
Advantages
- Readily welded — 85/100, better than 79% of aluminum grades
Limitations
- Limited ductility — 3%, worse than 79% of aluminum grades
- Low strength — 125 MPa (18.1 ksi), worse than 75% of aluminum grades
ER4009 properties
Typical room-temperature values for ER4009-AW; bars are the position among aluminum grades.
Physical3
ER4009 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 546°C (1,015 °F).
Mechanical10
ER4009 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
ER4009 is rated for continuous service to 150°C (302 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 22.4 µm/m·K (12.4 µin/in·°F).
Electrical3
ER4009 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of ER4009 takes about 158 MJ of energy and emits 11.5 kg of CO₂ — less than 93% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
ER4009's machinability is good (60/100, worse than 51% of aluminum grades); weldability excellent (85/100); formability fair (45/100).
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. ER4009 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ER4009
Is ER4009 easy to machine?
Weld deposits machine like C355 — sharp PCD or polished carbide tooling, high speed, flood coolant; the primary Si particles are abrasive to HSS.
Can ER4009 be welded?
Designed for GTAW/GMAW of C355/A356/A357 castings; preheat 100–150 °C on heavy sections, keep interpass low, and plan a full post-weld T6 (solution ~525 °C, quench, age) for rated strength.
Can ER4009 be formed, bent or molded?
Supplied only as drawn wire or cut rod — no forming application; keep wire clean and dry and re-clean oxidised surfaces before use to avoid weld porosity.
ER4009 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 |
|---|---|---|
| Si | 4.5 – 5.5 | 5 |
| Cu | 1 – 1.5 | 1.25 |
| Mg | 0.45 – 0.6 | 0.5 |
| Fe | ≤ 0.2 | |
| Mn | ≤ 0.1 | |
| Zn | ≤ 0.1 | |
| Ti | ≤ 0.2 | |
| Be | ≤ 3×10⁻⁴ | |
| Others (each)max each | ≤ 0.05 | |
| Others (total)max total | ≤ 0.15 | |
| Alremainder; chemistry corresponds to C355.0 casting alloy | balance |
What surface finishes work on ER4009?
Grind/blend flush before anodizing; expect dark, mottled anodic films from the Si+Cu chemistry, so use chromic/hardcoat or paint rather than decorative colour anodize.
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 ER4009 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- AWS A5.10 ER4009
- Other
- 4009
How much does ER4009 cost?
ER4009 is a high-cost aluminum ($$$$), pricier than about 78% 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.
ER4009 — frequently asked
What is ER4009 used for?
ER4009 is typically used for A356/A357 casting repair, automotive cast wheel welds and cast housing repair. In short: casting-matched Al-Si-Mg filler; heat-treatable weld deposit; for C355/A356 repair.
What is the yield strength of ER4009?
ER4009 has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is ER4009 easy to machine?
Reasonably — machinability is rated good (60/100, worse than 51% of aluminum grades). Weld deposits machine like C355 — sharp PCD or polished carbide tooling, high speed, flood coolant; the primary Si particles are abrasive to HSS.
Can ER4009 be welded?
Yes — weldability is rated excellent (85/100). Designed for GTAW/GMAW of C355/A356/A357 castings; preheat 100–150 °C on heavy sections, keep interpass low, and plan a full post-weld T6 (solution ~525 °C, quench, age) for rated strength.
What surface finishes work on ER4009?
Grind/blend flush before anodizing; expect dark, mottled anodic films from the Si+Cu chemistry, so use chromic/hardcoat or paint rather than decorative colour anodize.
Can ER4009 be formed, bent or molded?
Supplied only as drawn wire or cut rod — no forming application; keep wire clean and dry and re-clean oxidised surfaces before use to avoid weld porosity.
What is the maximum service temperature of ER4009?
ER4009 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 ER4009-AW and ER4009-T6?
AW is the default condition — default condition for field or in-service repair of castings where no furnace cycle is possible; moderate strength, low ductility. T6: the reason ER4009 exists — full C355-T6 cycle on the repaired casting gives weld metal strength close to the parent material. Yield strength is 125 MPa in AW versus 215 MPa in T6.
How much does ER4009 cost?
ER4009 is a high-cost aluminum ($$$$), pricier than about 78% 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
- AWS A5.10/A5.10M — Welding Consumables — Wire Electrodes, Wires and Rods for Welding of Aluminium and Aluminium Alloys — American Welding Society (2021)
- AMS 4189 / Aluminum Association Registration Record of Filler Alloys — SAE / The Aluminum Association (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (C355.0 data) — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (aluminium filler selection) — ASM International (1993)
- Aluminium filler metal selection and property guides — Lincoln Electric / ESAB / Indalco (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.