What Is An Arc In Welding?

When talking about welding, the arc is an essential component. Over 1 million individuals in the United States are employed in the welding industry and it is estimated that around 85 percent of all welding is done with an arc.

But what exactly is an arc in welding and how do you use it? In this article, we’ll explore the answer to this question and much more!

What is an Arc in Welding?

Arc welding is a fabrication process that uses electricity to form an electric arc between an electrode and two metals across the surface to be joined.

This forms a circuit and a high-temperature arc that melts and uses the filler material to join the metals when they cool. Arc welding is one of many popular welding processes used to join metal parts in fabrication, construction, and other applications.

How Does an Arc in Welding Work?

The electrode is a consumable wire or rod containing various fluxes, metals and alloys. As the electrical current flows through the electrode material and across the gap between the electrode and the workpiece, a high-heat arc is created.

This melts the electrode and its filler material, the base mettle and everything the arc touches. As the molten material cools, it forms a hard joint between the two parts. The type of current used in arc welding is DC (direct current).

It can be either straight polarity (electrode positive) or reverse polarity (electrode negative).

Types of Arc Welding Processes

There are various types of arc welding processes. The most popular include:
  • Shielded Metal Arc Welding (SMAW): also known as “stick” welding, SMAW is the simplest and most common type of arc welding.

    It is a manual welding process that uses a consumable electrode covered with a flux to lay the weld.

  • Flux-Cored Arc Welding (FCAW): similar to SMAW, FCAW also uses a consumable electrode but the electrode core contains flux material that forms a protective shielding as it burns.

    It is a faster process than stick welding and can be used in all positions.

  • Gas Metal Arc Welding (GMAW): commonly known as MIG (metal inert gas) welding, GMAW uses a consumable wire electrode and an external shielding gas, such as argon or carbon dioxide, to keep the weld area free from contaminants.
  • Gas Tungsten Arc Welding (GTAW): also known as “TIG” (tungsten inert gas) welding, GTAW uses a non-consumable tungsten electrode and an external shielding gas to protect the weld pool.
  • Submerged Arc Welding (SAW): this process uses a consumable electrode and a large, flat metal surface to lay the weld. It is a highly efficient form of welding and is commonly used to weld thick materials.
The choice of which type of arc welding process to use depends on the metal thickness, metal composition, welding position, acceptable welding speed and desired weld quality.


Arc welding is an important and popular process for joining metals together. There are a variety of arc welding processes that can be used, depending on the specific requirements of the application. Arc welding is a safe and effective method of joining metals, as long as all safety precautions are followed. Citation URLs: https://www. thefabricator. com/thefabricator/article/arcwelding/what-is-arc-weldinghttps://www. millerwelds. com/resources/welding-dict/types-of-welding-processes

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