Aluminium welding wire is one of those decisions that looks simple until you’re halfway through a job and the weld is porosity-riddled or cracking at the joint. Getting it right upfront saves time, material, and rework.
At Star Sheetmetal in Brooklyn, Melbourne, our team handles aluminium across welding and fabrication services for structural, industrial, and custom projects, with over 26 years of hands-on experience. Here’s what you need to know.
Quick Overview
- What it is: Aluminium welding wire is a filler metal used in MIG (GMAW) welding to join aluminium alloys, selected to match the base material
- Who it may apply to: It may suit fabricators, trades, and industrial operators working across structural, marine, or general aluminium welding applications
- What it involves or may help with: Choosing the right grade can improve weld strength, corrosion resistance, and feed consistency across different aluminium alloys
- What influences outcomes: The base alloy, application environment, and equipment setup all affect which wire performs best
- What guides next steps: Grade selection, diameter, and shielding gas requirements all need to be confirmed before committing to a wire for a project
Keep reading to understand the key grades, what they’re suited to, and what to watch for when setting up.
What Are the Main Grades of Aluminium MIG Wire?
Three grades cover the majority of aluminium welding applications in Australian fabrication: 4043, 5356, and 5183. Each is classified under AS/NZS 18273 for aluminium welding wire, the Australian and New Zealand standard for aluminium welding consumables.
ER4043 contains roughly 5% silicon, which gives it excellent fluidity, crack resistance, and a smooth weld pool. It’s well suited to 6xxx series alloys and situations where minimal distortion matters. One trade-off: it produces a darker finish after anodising, so it’s not the first choice where post-weld anodising is planned.
ER5356 is the most widely used general-purpose aluminium MIG wire. It offers high strength and good corrosion resistance, and it feeds more reliably through the torch because it’s stiffer than 4043. It’s the standard choice for structural aluminium welding, vehicle fabrication, and most workshop applications.
ER5183 is the marine-grade option. It’s designed for high-strength welding of 5083 alloys and delivers excellent corrosion resistance, particularly in saltwater environments. It’s commonly specified for shipbuilding, marine structures, and cryogenic applications.
Setting Up for Aluminium Welding Wire
Wire grade is only part of the equation. Aluminium wire is significantly softer than steel, which creates feeding challenges if the equipment isn’t configured correctly. Getting your MIG welder setup right for aluminium before you strike an arc eliminates the most common problems.
Key setup requirements:
- Liner: Replace steel liners with a Teflon (PTFE) liner. Steel liners cause the soft aluminium wire to catch and bird-nest at the drive rolls.
- Drive rolls: Switch to U-groove rolls. Standard V-groove rolls deform aluminium wire under feed pressure.
- Shielding gas: Use 100% argon. Any CO2 content in the gas causes porosity and poor bead appearance on aluminium.
- Torch length: Keep it to 3 metres where possible. The longer the feed path, the greater the risk of wire feeding issues.
Choosing the Right Wire for Your Application
A quick guide:
- General fabrication: ER5356
- 6xxx series alloys or thin gauge work: ER4043
- Marine, shipbuilding, or cryogenic applications: ER5183
- Post-weld anodising required: ER5356
When in doubt about which grade suits your aluminium alloys or application, the base metal specification and the service environment are the two most important deciding factors. For complex or structural aluminium MIG welding jobs, confirming the wire classification against your project specifications before fabrication begins is always the right starting point.
Talk to the Team at Star Sheetmetal
Whether you’re working through a straightforward aluminium MIG job or a more complex structural or industrial application, choosing the right aluminium welding wire from the start protects the integrity of the finished piece.
Star Sheetmetal in Melbourne has the experience and equipment to handle aluminium fabrication and welding across a wide range of projects. To discuss your requirements with our team, get in touch online or contact us on (03) 9000 0280 or 0433 217 574.
Frequently Asked Questions
What diameter aluminium welding wire should I use?
The most common diameters for aluminium MIG wire are 0.9 mm, 1.0 mm, and 1.2mm. For most fabrication shop work in Australia, 1.0mm or 1.2mm is preferred over 0.9mm because the thicker wire is stiffer, feeds more reliably, and is less prone to deforming in the liner. Thinner wire suits lighter-gauge material and lower-amperage machines, but demands a more careful setup to avoid feed problems.
Can aluminium welding wire be used with a standard MIG torch, or does it need a spool gun?
A standard MIG torch can work for aluminium welding, provided it is fitted with a Teflon liner, U-groove drive rolls, and aluminium-specific contact tips. That said, for torch runs over approximately 3 metres, or for production volume work, a spool gun is a more reliable option. A spool gun mounts the wire spool directly at the torch head, reducing the feed distance to a few centimetres and eliminating most feeding problems associated with soft aluminium wire.
References
Weldclass Australia. (n.d.). ‘Aluminium MIG Welding Wire Range’. Weldclass Australia. Melbourne, VIC: Weldclass. https://www.weldclass.com.au/category/29-mig-wire-aluminium
AIMS Industrial Supplies. (2026). ‘MIG Welding Guide: Settings, Wire, Gas and Technique’. AIMS Industrial Supplies, 30 April. Sydney, NSW: AIMS Industrial Supplies. https://aimsindustrial.com.au/blogs/product-guides/mig-welding-guide
Welding Industries of Australia. (n.d.). ‘MIG Welding Aluminium’. Welding Industries of Australia. Melbourne, VIC: Welding Industries of Australia. https://welding.com.au/mig-welding-aluminium