Welding 101 Practice Test

Travel speed in SMAW controls how much heat is put into the joint per unit length. When you weld faster, the arc spends less time on each spot, so the heat input per inch is reduced. That cooler, shorter heat input means the molten pool doesn’t penetrate as deeply and doesn’t spread as much, giving a bead that is narrower and flatter with less penetration. If you slow down, more heat is deposited, the molten metal flows more, and penetration increases, often producing a wider and more convex bead.