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What is Undercut And How To Prevent it!

Undercutting is a common issue for welders and is something we get asked about regularly here at

Undercutting is a groove that develops at the base or root of the metal and happens when the metal weld fails to fill in the groove. This can cause cracks in your weld, with areas that can trap water and dirt and reduce the strength of the joint even further. It is an issue which can affect both newbie and experienced welders and can be a costly and lead to a decrease in productivity.

But what causes undercutting? One of the most common reasons is that your amperage is too high. With stick, it could be that the electrode is too hot, heating up the base material too much. With MIG, it could be that the voltage or wire feed speed is too high. Other causes are that the work angle or travel speed are incorrect, or your manipulations are inconsistent.

In this video, Beau talks about how to prevent undercut. Starting with amperage, then moving on to other causes such as work angle, travel speed, manipulations, consumables, and material preparation. Let us know what you think! WATCH ON YOUTUBE!

For the purposes of this video, Beau used his Lincoln Electric equipment. Lincoln Electric is one of the industries experts and has over 100 years’ worth of experience in the welding industry. They offer everything you need for your welding and filling needs, and their expertise will help you find the right tools, equipment and techniques to help you prevent undercutting. This ensures, your welds are good, strong, and your business is profitable.

To learn more about Lincoln Electric equipment, filler metals, welding techniques and more, you can visit their Welding and Cutting Resources centre here:


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