Which joint configuration is least likely to be used in structural applications?

Edge joints are typically used in applications where material thickness is minimal, allowing for welding of overlapping edges or surfaces. However, in structural applications, the demand for strength, load-bearing capabilities, and overall performance often necessitates the use of more robust joint configurations.

Corner joints, lap joints, and butt joints are more favored in structural contexts because they provide better load distribution, higher strength, and greater resistance to stress and fatigue. For example, butt joints allow for full penetration, resulting in the strongest possible weld, and lap joints can distribute loads over a larger area, which is advantageous in construction and heavy fabrication. Corner joints are also used due to their simplicity in connecting two perpendicular members.

In contrast, edge joints do not offer the same level of strength or stability as these other joint types, making them less suitable for structural applications where safety and durability are critical factors. Thus, the least likelihood of being used in such contexts makes edge joints the correct answer.