In welding, weld metal protrusion beyond the fusion line at the weld toe is called:

• A. Overlap
• B. Undercut
• C. Reinforcement
• D. Incomplete fusion

Answer: (A)

In weld geometry, the term describes metal that sticks out past the edge of the joint at the weld toe and does not fuse to the base metal. This overhang is called overlap because the weld bead extends beyond the fusion line rather than being properly integrated with the base metal. It’s a defect that can create stress concentrations and trap moisture or contaminants.

This differs from reinforcement, which is extra weld metal purposely built up above the surface and intended to be fused. Undercut is a groove melted into the base metal along the weld toe, not a protrusion beyond the fusion line. Incomplete fusion means the weld metal didn’t fuse to the base metal where they should join, creating a gap.