How Does an Arc Welder Work?

Arc welding is the process of fusing together different metals with an arc, or a beam of heat produced by an electric current. Arc welding is a broad term that includes several different processes.

Welding is a catch-all term for many different ways of fusing metals together. One of those is arc welding. 

Welders need to understand the different processes included in arc welding, how to conduct this process and how an arc welder works. This guide will give you an introduction into this all-important welding technique.

What Is Arc Welding?

Before you get into the nuances of arc welding, it’s important to understand this process thoroughly.

Arc welding uses an electric arc, using direct or alternating currents to generate heat between the electrode and base material. The arc generates heat, which fuses the metals together. 

There are other types of arc welding, such as arc welding that uses a plasma arc, a gas column, or a laser arc (more on the different types of arc welding in a bit). However, all types of arc welding follow a similar process.

The heat generated by the electrical arc often reaches thousands of degrees Fahrenheit, hot enough to melt the metal along the line. As the metal cools, the melted parts solidify and form a solid, fused joint that is now completely secure. To create a welded line, you guide the arc welder along the joint, keeping it steady either manually or mechanically as the electrode directs the beam.

MIG Welding Advantages And Disadvantages

What Are the Types of Arc Welding?

Arc welding is a catch-all term for a few different types of welding. Here are some of the main types of this technique. Usually, the biggest difference is the electrode type and the power supply that creates the arc.

1. Shielded Metal Arc Welding

Shielded metal arc welding is a consumable electrode arc welding type, where the electrode melts as you use the welder. Shielded metal arc welding, also called stick welding, uses electrode sticks to conduct the arc. These sticks melt as you weld. When they are done, you must manually replace the sticks in your welder.

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2. Gas Metal Arc Welding

Gas metal arc welding, also called metal inert gas or MIG welding, is another type of consumable electrode arc welding. Instead of using a stick electrode, this type of welding pumps gas to the torch, which conducts the arc through a wire. With MIG welding, you must be careful of the type of wire you are using since it will melt into the metal you are welding.

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3. Flux-Cored Arc Welding

Flux-cored arc welding is a form of arc welding that innovates on MIG welding. It also uses a wire to form the electrode, which is hollow and full of flux, or a chemical purifying agent. As the flux heats up, it creates gas, meaning that you usually don’t need a separate gas tank for this type of welding.

4. Submerged Arc Welding

Submerged Arc Welding also uses flux material and a wire to conduct the arc. The flux coats the weld pool, which ensures steadier conduction of the arc and minimizes splatter.

5. Electro-Slag Welding

This very specific type of welding is complex and only used when you have to weld together vertical joints of very specific material. Instead of putting flux in the wire or electrode, you insert it in between the joints. Then, you thread the electrode into the gap and melt the flux, fusing the joint.

6. Arc Stud Welding

Arc stud welding is another specialty form of arc welding that is just used to weld fasteners, or studs, into their places. Instead of relying on a separate electrode, the stud itself acts as the electrode that conducts the arc and melts with the surrounding surface.

7. Tungsten Inert Gas Welding

Tungsten inert gas welding is one of two types of non-consumable electrode welding, meaning the electrode directing the arc is reusable. This form of welding uses a tungsten electrode and a separate filler rod that is consumed during the process.

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8. Plasma Arc Welding

One of the most modern types of welding, plasma arc relies on plasma generated by ionized gas to weld materials together.

Components of Arc Welding

There are a few different components of an arc welding, including:

  • A welding machine, which generates the DC or AC currents
  • Electrode and work cables
  • Electrode (consumable or non-consumable)
  • The electrode holder
  • The arc

How Does an Arc Welder Work?

The process of welding using an arc welder starts at the power source. The welding machine generates AC or DC currents, which power the arc. The machine has two studs, a positive and a negative stud.

The current passes through the electrode cable before reaching the electrode itself. The electrode is guided by the electrode holder, which in turn makes it possible for a human to hold on to the electrode. Once it reaches the electrode, the DC or AC current turns into the arc, which fuses the metal.

The other important component of an arc welder setup is the work cable. The work cable, sometimes called the grounding cable, is attached to the opposite stud on the welding machine from the electrode cable.

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Other Necessary Equipment

Besides the equipment needed to power an arc welding machine, there are a few other pieces of equipment that you need to safely operate a welder, including:

  • A grounding cable for the welding machine to prevent electric shock
  • Protective shielding gas, flux, or slag to prevent the molten metal from coming in contact with the air and becoming contaminated
  • Replacement electrodes or wires if you are using consumable electrode arc welders
  • Safety equipment such as visors, gloves, and clamps for your equipment

Final Thoughts

Arc welding is one of the most common types of welding due to its versatility and portability. Those same qualities make it a great choice for beginner welders. If you want to get started with welding, this is what you need to know about this all-important technique.