In MIG welding, which adjustment flattens the welding bead?

• A. Increase The Wire Feed Speed
• B. Increase The Voltage
• C. Decrease The Voltage
• D. Change Shielding Gas

Answer: (B)

In MIG welding, how the bead looks is all about heat input, which is largely controlled by voltage. Raising the voltage increases the arc length and the heat entering the molten pool. That extra heat lets the molten metal flow and spread along the joint more evenly, making the bead wider and flatter rather than tall or overly rounded. So adjusting voltage upward tends to flatten the bead when the weld is too peaked or concave.

Increasing the wire feed speed would add more filler metal but doesn’t inherently flatten the bead; it can make the bead thicker or cause other shape changes. Decreasing the voltage narrows the arc and reduces heat, which typically makes the bead more pronounced and concave. Shielding gas mainly affects arc stability and penetration, not bead flatness directly.