MIG Welding Polarity

MIG Welding Polarity

In MIG welding, polarity is an important aspect that must be taken into account. The correct polarity must be used in order for the welding process to work correctly.

 There are two types of polarity that can be used in MIG welding:

  • Direct current (DC): DCEP (also called Reverse polarity) and DCEN (also called Straight polarity),
  • alternating current (AC): used for aluminum and other highly oxidizing alloys

 DC is the most common type of polarity used in MIG welding, as it provides a more stable arc. AC is less common, but can be used in certain situations where DC cannot be used such as Aluminum welding, where AC gives better cleaning action.

Related reading: Types of Welding Polarity.

MIG Polarity

MIG polarity when welding is mostly Electrode positive (DCEP) as it provides good arc characteristics although electrode negative can also be used.

The differences between Electrode positive (Reverse MIG polarity) and Electrode negative (Straight MIG Polarity) are given in below table:

Effect of MIG Polarity: DCEP vs. DCEN
Characteristics DCEP (Electrode Positive) DCEP (Electrode Negative)
Weld Penetration Good  Poor
Rate of weld deposition Low  High
Welding spatters Low  High
Excessive weld metal  Low
Oxide cleaning effect Yes  No
 Welding arc force High  Low

MIG welding polarity chart

If you’re a welder, then you know that there are many factors to consider when striking an arc. One of the most important is choosing the right welding polarity using above polarity chart.

A MIG welding polarity chart lists the different types of metal and the recommended polarity setting for each. This way, you can quickly and easily find the right setting for your project.

Plus, a MIG welding polarity chart can help you troubleshoot any problems you may be having with your welds.

So whether you’re a beginner or an experienced welder, a MIG welding polarity chart is a valuable tool to have on hand.

What Polarity is MIG welding?

Polarity used in MIG welding is the direction of the electric current flow through the arc. The three types of polarity used in MIG welding are:

  1. DCEN (Direct Current Electrode Negative),
  2. DCEP (Direct Current electrode Positive), and
  3. AC (Alternating Current).

DCEN polarity is when the electrode, or wire, is negative and the workpiece is positive. The arc forms at the tip of the electrode and moves to the workpiece.

This type of polarity produces more heat at the base metal, making it ideal for thicker metals.

DCEP polarity is when the electrode is positive and the workpiece is negative. The arc forms on the workpiece and moves to the electrode.

This type of polarity produces more heat at the tip of electrode, making it ideal for thinner metals.

Why reverse polarity is used in mig welding?

When MIG welding, the electrode is connected to the positive terminal of the welder and the work piece is connected to the negative terminal. This is known as reverse polarity.

There are a few reasons why reverse polarity is used in MIG welding. First, it helps to create a more stable arc. Second, it increases deposition rates. And third, it reduces spatter.

First, reverse polarity actually provides a more stable arc. This is because the electrons flow from the electrode to the workpiece, rather than from the workpiece to the electrode. This results in less spatter and a more consistent weld bead.

Second, reverse polarity increases welding deposition rate.
Finally, reverse polarity gives a smooth arc with low welding spatters thus improving welding quality.

So if you’re looking for a more stable arc and higher deposition rates, then reverse polarity is the way to go.

The reasons why Straight polarity (DCEN) is not used in MIG Welding are:

  • DCEN produces a lower arc voltage and can be difficult to penetrate thicker metals with.
  • Straight polarity results in high welding spatters.
  • The welding quality is poor with straight polarity in MIG welding.
  • There is no cleaning action by welding arc in straight polarity.
  • The welding arc force is low in DCEN or straight polarity.

which dc polarity is most commonly used in mig welding due to it’s stable arc, low spatter, good weld bead characteristics, and greatest depth of penetration for the widest range of amperages?

MIG welder polarity

MIG welders use three types of polarity:

  1. Reverse Polarity
  2. Straight Polarity
  3. AC Polarity

MIG welding aluminum polarity

MIG welding aluminum is a bit more complicated than welding other metals. The main difference has to do with polarity.

MIG welding aluminum polarity is mainly AC Polarity as it provides best oxide cleaning action of aluminum surface.

This results in high quality welds with minimal efforts for surface cleaning. Modern MIG welding machines uses pulse welding current to provide stable welding arc with surface cleaning action for MIG Welding.

Related reading: How to clean Aluminum Oxide.

DCEP or reverse polarity can also be used for MIG welding aluminum, but it requires precleaning of aluminum surface. The surface shall be free from oxide layer before welding.

MIG welding electrode positive or negative?

MIG welding electrode positive or negative is a question that often plagues beginner welders. The answer, however, is quite simple.

When it comes to MIG welding, the electrode is almost always going to be positive. This is because a positive charge creates a more powerful arc, which is necessary for MIG welding.

Positive electrode also provides better penetration and less welding spatters. A negative charge can be used in some cases, but it is not as common.


MIG welding, or Metal Inert Gas welding, is a popular type of welding that uses an electrode wire and an electric power source to create a stable arc. The arc is used to melt the base metal and the filler metal, which are then joined together.

MIG welding can be done with either direct current (DC) or alternating current (AC), but DC is most common. DC can be either direct current electrode positive (DCEP) or direct current electrode negative (DCEN).

DCEP is the most common type of DC used for MIG welding, as it provides a more stable arc. However, DCEN can be used in some cases where DCEP cannot, such as when welding thin metals.

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