Which factors most directly influence bead width in GMAW?

• A. Wire diameter and travel angle
• B. Gas type only
• C. Ambient humidity
• D. Base metal color

Answer: (C)

Bead width in GMAW comes from how much metal is deposited and how the heat from the arc is spread across the weld pool. The wire diameter sets the amount of metal that can be delivered per unit length—the larger the diameter, the more metal is deposited and the wider the bead tends to be. The travel angle of the torch affects how the heat is distributed in the molten pool; a more open angle tends to widen the bead by spreading heat and material outward, while a steeper angle concentrates heat and narrows the bead. Gas type mainly affects shielding and arc stability, not the bead width itself, and ambient humidity or base metal color do not directly set bead dimensions. So the factors that most directly influence bead width are the wire diameter and the travel angle.