Mig 5356 FAQs
Straight answers on choosing, feeding, storing and troubleshooting 5356 (aluminium-magnesium) MIG wire.
When should I choose 5356 wire rather than 4043?
5356 is an aluminium-magnesium filler. It gives a stronger weld than the aluminium-silicon 4043 and is the usual choice for structural work, for common alloys such as 6061 and for most 5000-series plate. It is also the better option if the part will be anodised afterwards.
4043 is generally preferred where cracking resistance matters or the part sees elevated temperatures. Where the base alloy is specified in a drawing or code, follow the filler selection chart for that alloy and the job's service conditions.
Will a 5356 weld match the colour of an anodised part?
Usually it will be a much closer match than a silicon-bearing filler. The silicon in 4043 and 4047 normally leaves the weld dark grey after anodising, whereas the magnesium in 5356 lets the weld take the anodised finish in a similar colour to many common base alloys.
The match is never perfect on every alloy, so if appearance matters, weld and anodise a test piece first. Tell the anodiser which filler was used.
Can I use 5356 wire on parts that run hot?
Not for sustained heat. Aluminium filler with more than about 3 percent magnesium can become prone to stress corrosion cracking if it is held above roughly 65 degrees C (150 degrees F) for long periods, and 5356 sits above that magnesium level. Other high-magnesium fillers share the same limit.
For parts in warm service, such as near engines or exhausts, consider a lower-magnesium or aluminium-silicon filler, or ask the designer. The limit applies together with other conditions such as a corrosive environment, so it is a design question, not a rule of thumb for every job.
Why does my aluminium wire tangle or stop feeding, and how do I prevent it?
Aluminium wire is soft, so it crushes and buckles in a feed path built for steel. The usual remedies are U-groove drive rolls with light pressure, a smooth plastic (such as PTFE) liner instead of a steel one, a clean, correctly sized contact tip made for aluminium, and a short, straight cable.
If the feed path is long, a push-pull torch or a spool gun, which keeps the wire path short, often cures it. If the wire still tangles, check the liner, the tip bore and the roll pressure before changing the machine settings.