ER4043 and ER5056 Aluminum weldiong wire for general aluminum works
Should I use 4043 or 5356 filler alloy?
As a basic description we can say that 4043 is an aluminum filler
alloy with 5% silicon added and that 5356 is an aluminum filler
alloy with 5% magnesium added.
There are some misconceptions within the industry that you can
successfully weld any aluminum base alloy with either 4043 or 5356
filler alloy. I must start by saying that this is not the case.
However, there are many common structural aluminum base alloys that
can be welded with either 4043 or 5356. One such alloy is 6061.
The question here is when should we choose one of these filler
alloys over the other?
When the filler alloy selection chart allows the use of either 4043
or 5356 as filler for a specific base alloy, as a guide, we may
wish to consider the following facts about each of these filler
- 4043 should not be used if you are considering the best color match
after post weld anodizing, as this filler alloy will typically turn
dark gray in color after the anodizing process. 5356 will provide a
much closer color match after anodizing.
- 4043 is suitable for service temperatures above 150 Deg. F,
however, 5356, because of its 5% magnesium content is not suitable
for these elevated temperature applications.
- 4043 has lower ductility than that of 5356. This may be of some
consideration if forming, after welding is to be carried out.
- 4043 has lower shear strength than that of 5356. This may be of
consideration when calculating the size of fillet welds.
- 4043 is a softer alloy in the form of spooled wire, when compared
to 5356. Typically when Gas Metal Arc Welding, feedability will
become a less critical issue when feeding the more rigid 5356
- 4043 will typically provide a higher rating for weldability and
provide slightly lower crack sensitivity. 4043 will generally tend
to produce welds with improved cosmetic appearance, smoother
surfaces, less spatter and less smut. For this reason, it is
sometimes more appealing to the welder.