The weld feature that describes protruding weld metal beyond the fusion boundary at the toe is called:

• A. Reinforcement
• B. Overlap
• C. Undercut
• D. Overfill

Answer: (B)

Understanding how weld metal sits relative to the base metal is key here. The term for weld metal that sticks out past the surface of the base metal at the weld toe is reinforcement. It describes the extra height or crest of weld that rises above the base metal, along the toe line, giving a raised edge to the weld. This is different from overlap, which is when welded material beyond the joint edge is not properly fused to the base metal; undercut, a groove melted into the base metal at the toe, reduces throat thickness; and overfill refers to excessive filler metal filling the joint, not specifically the protrusion at the toe. So the protruding weld beyond the fusion boundary at the toe is reinforcement.