Consumables Corner: The secret behind those preset weld parameters on your power source

Q: Is there a general guideline for weld settings based on material type and thickness? I have seen that some small welding machines allow you to choose the material thickness and it will give recommended settings. How is that determined?

A: The short answer is no. There are many variables to consider before determining weld parameter settings, such as material type and grade, filler metal classification and diameter, shielding gas, welding position, weld joint and quality of fit-up, welder skill level, minimum and maximum heat input, and the postweld mechanical performance of the weld metal and base material.

The machines you're referring to are considered light-industrial or home hobbyist equipment. Typically, these types of machines are mostly used for repair work, autobody work, or small fabrications such as steel fences. Many of these applications do not require you to adhere to a welding code or specification that would dictate the welding parameters. Additionally, many of the individuals who would be using this type of equipment have little to no weld training or experience, so the manufacturer is trying to simplify the job for them.

The equipment manufacturers have based their preset welding parameters on previous testing of successful welds and integrated them into the equipment software. The data they are using would come from a procedure qualification record (PQR) or welding procedure specification (WPS). There are many tested and proven weld settings based on all the variables. Many older machines included a chart with recommended settings. In more modern machines, the manufacturers have programmed that information into the software.

In most of the machines, the software guides you step by step to determine the weld settings. You’ll have to input your welding process, filler metal type, wire diameter, and shielding gas. After you have entered the basic information, you adjust the wire feed speed (WFS) up or down, and on the display screen you will see the material thickness vary as you make those adjustments. When you increase WFS, the material thickness increases, which correlates to higher amperage, and conversely for lower WFS settings.

Once you have selected the approximate material thickness, the machine will determine a WFS and voltage setting as a starting point. These machines use a feature called a synergic line that determines voltage starting points based on the selected WFS and previously entered information, but it also allows you to fine-tune adjustments. These features combined simplify the process greatly for the welder, especially one who has limited experience.