What Is a 4043 Welding Rod Used For?

Written By: Liam Bryant

Reviewed By: Russell Egan

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When welding you need to change the welding rod you are using depending on the material, project type, and welding type you are working for. Looking at welding rods is very overwhelming as a beginner welder because they differ so widely in terms of tensile strength, penetration, and other properties. Plus, how are you supposed to decipher the welding rod numbers? 

Our site can help you understand the different welding rods by giving you insight into the properties of each rod you might be working with. 4043 welding rods are some of the best electrodes to work with when welding aluminum. They have a lower tensile strength making them great for delicate materials.

E4043 Welding Rod
  • DC+ Current
  • Flat, Horizontal, Vertical, and Overhead Positions
  • 40,000 PSI Tensile Strength

Here are more details about the 4043 welding rod and when you should have them in your workshop.

4043 welding rod

What Are the Properties of the 4043 Welding Rod?

The 4043 welding rod has some properties that set it apart from other welding rods you may already have in your workshop, such as the 7014 and 7018 welding rods. Let’s go through their properties one by one.


Welding machines send a polarized current through the electrode to complete the circuit when the arc touches the metal. That means your welding rod has to be compatible with the current you are using from your welding machine to get a good result when you’re welding. 

The 4043 welding rods work best with reverse polarity, or DCEP, currents. 

Tensile Strength

The biggest difference between 4043 welding rods and other types of electrodes is the tensile strength. As you may already know, you can tell the tensile strength of a welding rod from the first two numbers of a welding rod number. In the case of a 4043 welding rod, the tensile strength is 40,000 psi (pounds per square inch). 

That tensile strength is far lower than the strength of most common welding rods, such as the 7014 welding rod which has a tensile strength of 70,000 psi. The 4043 welding rods are not suited for welding hard materials such as steel because they don’t have the tensile strength to withstand the pressure of welding those materials.

However, the low tensile strength is not a defect but a feature of 4043 welding rods. The same “flaw” that makes it difficult to weld steel makes it better for welding softer materials such as aluminum. Aluminum is harder to weld for beginners because it is softer and more delicate than other metals. That means welding rods with lower tensile strength are better to avoid cracking the metal.


The 4043 welding rods have a medium penetration, making them a solid choice for multi-purpose welding. You won’t have to worry about penetrating too deeply and accidentally damaging the aluminum material you are working with. 

What Is a 4043 Welding Rod Suited For?

As mentioned above, 4043 welding rods are perfectly suited for welding lighter materials such as aluminum and aluminum alloys.

Besides having a low tensile strength and medium penetration, 4043 welding rods have other properties that make them ideal for these applications, including:

  • Affordability
  • Resistance to black smut
  • Not crack sensitive 
  • Compatibility with heat-treatable alloys
  • All positionality

These qualities make it easy to use a 4043 welding rod in a few different situations when working with aluminum, such as:

  1. Repairs
  2. Automotive welding

Repairing Aluminum and Alloys

The 4043 welding rods are one of the best choices for repairing materials made from aluminum or aluminum alloys. The 4043 welding rods are also compatible for working with silicon alloys.

This welding rod is great for repairs because it can work in all positions, meaning you don’t have to take the thing you are repairing apart. It creates a smooth weld without black smut or residue, so you can make repairs without damaging the surface.

Automotive Welding

Many autobody parts are made of thin sheet metals such as aluminum. When repairing those parts or putting them together, you can use a 4043 welding rod. You’re not limited to working on cars and can use 4043 welding rods for several personal vehicles, including bicycles.

The versatility, positionality, and easy welding experience of the 4043 welding rod make it easy to use in repair shops.

Types of Welding Suited for 4043 Welding Rods

You can use 4043 welding rods with a few types of welding, including:

  1. All position welding
  2. Repair welding
  3. TIG welding
  4. Casting welding

Final Thoughts

When welding aluminum, you have to use the right tools to meet the challenge of this metal. Aluminum is too fragile and pliable to hold up to regular welding. That is where a welding rod such as the 4043 welding rod comes in, which is perfect for aluminum due to its low tensile strength.