Guide On Welding Amperage Selection

(Last Updated On: January 8, 2021)

It can be intimidating to grasp all of the dials and automated readouts on the welding unit. The few controls are going to be easier on a stick welding machine than on a TIG machine. For different settings, a top-end TIG machine could have as many as 20 control knobs.

It can be very difficult for the inexperienced welder to set up a welding machine and change the settings, too, but they are needed for a certain weld. Stick welders, MIG welders, and TIG welders all have different front-of-the-machine controls. These are designed to change the amount of current necessary for a weld. But how do you know the amperage or voltage setting to which way you should set the system?

Setting the amperage on a welding machine depends on certain primary variables such as application and base material, welding method, and electrode, whether Stick (SMAW), MIG (GMAW)(* usually uses voltage setting), or TIG (GTAW).

You can set your welding machine and start laying a weld bead once you recognize these three key variables. We will address these three variables in detail in this post and include some “pro tips” along the way!

Foundation Content & Implementation

We will discuss the welding application, the base material, and how it relates to the amperage selection on a welding machine in this section.

The welding application (a type of welding method) will be defined in a wider context for this article. There is a clear connection between the soldering application and the amperage used in a weld. A highly technical TIG weld on a helicopter exhaust manifold, for example, would have a dramatically different amperage required than an oil pipeline, instance. The distinction would be between welding thinner exotic metals and welding the next pipe in series to a three-foot diameter pipe. Micro TIG welding and laser beam welding have similar applications where the amperage is very poor in TIG soldering.

However, since there is no electrical current flow inside the workpiece, there is no amperage at all in laser welding. In comparison, to achieve maximum penetration into the workpiece, MIG welding and Stick welding (and sometimes TIG welding) can use very high amperage settings.

For example, the welder is asked to weld a one-inch thick steel plate on a highway overpass to a steel girder. This is a critical structural weld, and it is necessary to achieve optimum weld penetration into the base metals.

Amperage is chosen for simplicity in such applications. e.g., in your workshop, you may want to MIG weld a sheet of metal to another sheet of metal, so you may be inclined to turn up the amperage to get as quickly as possible. This is not to suggest that speeding through a weld is good practice, but it is very normal to speed up a weld bead in a non-critical application.


The choice of amperage is not as frustrating and overwhelming as you would first think it is. Certain key variables, such as Application and Base Material, Welding Method, and Electrode, decide the amperage that should be used in a certain welding application.

With these key variables in mind, it should be no problem to find the correct amperage needed for the weld. As always, in your nearest welding shop, if you are still uncertain, there are various tools at your side, whether online, at a library, or my favorite.



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