GMA/MIG fillet welds are what shaped beads?

• A. Triangular
• B. Rectangular
• C. Circular
• D. Wavy

Answer: (A)

Bead geometry in a GMA/MIG fillet weld is triangular because the metal fills the corner between two members, forming two weld legs along each piece that meet at the root. When you view the weld in cross-section, the deposited metal fills upward from the root toward both faces, creating a wedge shape whose shortest distance from the root to the face is the throat. This results in a triangular profile for a typical fillet bead. A rectangular cross-section would imply filling a rectangular groove with parallel faces, which isn’t how a fillet weld fills a 90-degree corner. Circular describes a different weld form like a plug or groove, and a wavy pattern comes from weaving or technique issues, not the standard fillet bead.