What is CO2/MIG welding wire and what is its use?

This is a detailed page about MIG welding wire selection. It covers most electrodes that are commonly used in the field for:

Carbon steel

Stainless steel

Aluminum

MIG ESABWelder Electrode

MIG Welder Electrode

Most Widely Used MIG Welding Electrode Sizes

Typical MIG welding electrodes are a solid wire ranging from a thickness of .023 to .045. Some are much thicker for heavy industrial applications. The most common sizes most welders use are:

.023

.030

.035

.045

 

For most fabrication shops the .035 with is the most common. The smaller the electrode the less power you need from your machine to run. Just remember when it comes to MIG welding a single electrode size welds a wide range of metal thicknesses because it is the machine set-up that determines the metal thickness that will be welded.

MIG Welding Electrode Wire Selection Guide Chart

 

 

Welding Carbon Steels and Mild Steels

  • AWS Electrode Classification: ER70s-6

Shielding Gas: C25 (25% Carbon Dioxide and 75% Argon) or 100% Co2

 

Welding Stainless Steel

Stainless Steel Grades: 301, 302, 304, 305, and 308.

  • AWS Electrode Classification: ER308L and ER308LSi

Shielding Gas: C2 or 2% Carbon Dioxide and 98% Argon

Stainless Steel Grades: 309 Stainless and Welding Carbon Steel to Stainless Steel or Low Alloy Steels

  • AWS Electrode Classification: ER309L

Shielding Gas: C2 or 2% Carbon Dioxide and 98% Argon

Stainless Steel Grades: 304,305, 308, 310, 312, 314, 316, 317, 321, 347 and 348.

  • AWS Electrode Classification: ER316L and ER316LSi

Shielding Gas: C2 or 2% Carbon Dioxide and 98% Argon

Welding Aluminum

Aluminum Grades: 2014, 3003, 3004, 4043, 5052, 6061, 6062 and 6063. It may also be used to weld cast Aluminum grades 43, 214, 355 and 356.

  • AWS Electrode Classification: ER4043

Shielding Gas: 100% Argon

Aluminum Grades: 5050, 5052, 5056, 5083, 5086, 5154, 5356, 5454, 5456.

AWS Electrode Classification: ER5356

Shielding Gas: 100% Argon

Carbon Steel Electrode Selection and Choices

MIG Welding carbon steel or mild steels are typically welded with a ER70s-6” electrode using either 100% Carbon Dioxide gas or C25 gas that is 25% Carbon Dioxide and 75% Argon mixture. If you are welding a higher grade of carbon steel the minimum tensile strength is what usually changes. For example if you are welding high strength steel the “ER70S-6”would be a “ER90S-6” instead.

 

Carbon SteelER70S-6 Electrode Designation

The labelER70S-6represents the following:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

70– A minimum of 70,000 pounds of tensile strength per square inch of weld.

S -Solid wire.

6– The amount of deoxidizing agent and cleansing agent on the electrode. This is a copper coating on the electrode and there are different types too.

Stainless Steel MIG Welding Electrode Selection and Choices

MIG welding stainless steel has a variety of electrodes because it is used on a wide range of projects that require different types of stainless steel grades. It is also commonly welded to Carbon steel on the same jobs. For example a stainless steel brace that is welded to the building that holds stainless steel piping. Here are the different types of stainless steel electrodes. Stainless Steel is typically welded with the electrode classes and they are:

ER308L

ER309L

ER316L

ER308L and ER308LSi MIG Welding Electrode Designation and Uses

These stainless electrodes are mostly used for lower grade stainless steels 301, 302, 304, 305, and 308. It is typically used in industrial applications and it does get some rust spots from time to time. The wire designation is as follows:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

308 – The grade of the Stainless Steel Electrode.

L –Low Carbon. Carbon content is what gets the rust spots on stainless.

Si– (Optional) Sometime “Si” is added and that means high silicone content. Basically it helps the weld wash into the metal better.

 

ER309L and ER309Si MIG Welding Electrode Designation and Uses (Welding Dissimilar Metals)

The 309 series has a multi use designation because it is used to weld stainless steel to mild or stainless to carbon or low alloy steels. It welds stainless steel grades 304 through 310 when needed or welds dissimilar metals together where needed. The downside of using this electrode to weld steel to stainless is that the weld appearance is rough. The gas used most of the time is the same C2 or 2% carbon dioxide and 98% Argon. There are many other choices (some are better) for gas but the C2 is the most common used. Here is the electrode designation:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

309 – The grade of the Stainless Steel Electrode.

L –Low Carbon.

Si– (Optional) Sometime “Si” is added and that means high silicone content.

ER3016L and ER316LSi MIG Welding Electrode Designation and Uses

These stainless electrodes are mostly used for higher grade stainless steels mainly in the food industries and marine applications. The base metals the ER316 welds are stainless grades 304,305, 308, 310, 312, 314, 316, 317, 321, 347 and 348. As for gasses the C2 (2% carbon dioxide and 98% Argon) is the most widely used. There are many other mixtures to choose from and that all depends on you welding supplier has to offer. The wire designation for the ER316L and the ER316LSI are as follows:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

316– The grade of the Stainless Steel Electrode.

L –Low Carbon. Carbon content is what gets the rust spots on stainless.

Si– (Optional) Sometime “Si” is added and that means high silicone content.

 

Aluminum MIG Welding Electrodes Choices and Wires

MIG welding aluminum electrodes selection is pretty straight forward. There are two typical choices and they are:

ER4043

ER5350

 

As for gas choices it is always 100% Argon gas. If you are welding aluminum thicker then 1/2 of an inch then you may want to try a Argon Helium mix. In most cases 100% Argon is what most shipyards, power plants and fab shops use no matter what the thickness of the aluminum is. Here are the aluminum electrode designations:

ER4043 MIG Welding Electrode Designation and Uses

The ER4043 is the most commonly used MIG filler wire. It welds aluminum grades 2014, 3003, 3004, 4043, 5052, 6061, 6062 and 6063. It may also be used to weld cast aluminum grades 43, 214, 355 and 356. The gas used is always 100% Argon and in rare cases a helium/Argon mix may be used on base metals thicker then ½ of a inch. Electrodes classification and designation is as follows:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

4– The series of the aluminum. This electrode is made from a 4000 series aluminum.

043 – This number indicates the amount of silicone added to the electrode. 4000 series of aluminum alloys have silicone added to make that grade.

 

ER5350 MIG Welding Electrode Designation and Uses

The ER4043 is the most commonly used MIG filler wire. It welds aluminum grades 5050, 5052, 5056, 5083, 5086, 5154, 5356, 5454, 5456. In most cases the gas used is always 100% Argon and in rare cases a helium/Argon mix may be used on base metals thicker than ½ of a inch. Electrodes classification and designation is as follows:

ER– An electrode or filler rod that is used in either a MIG wire feed or TIG welding.

5– The series of the aluminum. This electrode is made from a 5000 series aluminum.

356 – This number indicates the amount of Magnesium added to the electrode. 5000 series of aluminum alloys have Magnesium added to make this alloy.

 

 

 

 

 

For more information on the price of co2 welding wireand to buy co2 wire and other Delta wire products, call 09121147793.