In GTAW, how is the bead decreased?

• A. decreasing the voltage.
• B. increasing the voltage.
• C. increasing the amperage.
• D. decreasing the amperage.

Answer: (D)

Bead size in GTAW is controlled by the heat put into the workpiece. Heat input mainly follows the current: more current means more heat, which grows the bead and increases penetration. To decrease the bead, you reduce the heat input by lowering the amperage, which cools the process and produces a smaller bead. Voltage and arc length can influence the arc to some extent, but they don’t control bead size as directly as amperage. If you need even less bead, increasing travel speed also helps by spending less time depositing material per inch, but the direct method from the given options is decreasing the amperage.