Which of the following is not classified as a type of weld joint?

The correct choice identifies that a lap joint is not classified as a type of weld joint. In welding terminology, the primary classifications of weld joints include butt joints, fillet joints, and tee joints.

A butt joint is where two pieces of material are aligned edge-to-edge and welded together, primarily used for joining flat pieces. A fillet joint is formed when two pieces of material are joined at an angle, creating a triangular cross-section at the weld, commonly used for corner and edge welds. A tee joint is created when one piece is perpendicular to another, forming a "T" shape for the weld.

In contrast, a lap joint involves overlapping two pieces of material and welding them together. While lap joints can be welded, they typically belong to a broader category of joint types classified under mechanical fasteners rather than fusion welding joints. Understanding this distinction helps clarify why the lap joint does not fit within the traditional classification of weld joints.