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Aluminum Welding Guide
View technical guides for guidance on welding various metals and selecting the right Hobart Brothers filler metal solution for your application.
Aluminum Welding Guide
Filler Metal – Guidelines For Selecting The Most Appropriate Filler Metal (4043/4943 or 5356)
Selecting the correct filler alloy for aluminum is based on the operating conditions of the finished welded component. It is therefore essential to have the answers to some basic questions prior to the selection of the most appropriate filler metal.
- What is the aluminum base metal designation?
- Will the welded component be exposed to sustained elevated temperature? 3. Will the completed weldment be subjected to post weld anodizing?
- Will shear strength, ductility, and toughness be of prime consideration?
- Is post-weld heat treatment to be performed?
Alloys 4043/4943 and 5356 are used in over 85% of all aluminum weldments. If the technical requirements of the weld can be met with either 4043/4943 or 5356, use one of these two alloys because they are readily available and are the least expensive to purchase. Also consider using the largest recommended diameter wire because the larger sizes are also less expensive.
When welding the 5xxx and 6xxx series base metals the following considerations should be made when selecting the most appropriate filler metal:
- For 6xxx series base metals, and 5xxx series base metals containing up to 2.5% (nominal) Magnesium use either 4043/4943 or 5356.
- For 5xxx series base metals containing more than 2.5% (nominal) Magnesium use 5356 filler metal and do not use 4043/4943 filler metal.
- For good anodized color matching use 5356.
- For higher ductility and toughness use 5356. This will increase resistance to crack propagation.
- For long term elevated temperature exposure above 150°F use 5554 or 4043/4943. Do not use 5356.
- For higher shear strength use 5356 or 4943. A rule-of-thumb is that it takes three fillet passes of 4043 to equal the shear strength of one pass of 5356.
- For reduction of termination and shrinkage cracking use 4043/4943 or 4047.
- For reduction of welding distortion use 4043/4943 or 4047.
- For brighter welds with less welding “smut” use 4043/4943.
- For better feedability through the welding gun use 5356. 5356 is twice as stiff as 4043/4943 and therefore feeds better. However, MAXAL’s 4043/4943 has excellent feedability.
Note: For more detailed information on filler metal selection refer to the Hobart selection chart in the back of this book.