Cracks, suckback, undercut, and overlap are discontinuities found in:

• A. Castings
• B. Forgings
• C. Extrusions
• D. Weldments

Answer: (D)

In welding, discontinuities like cracks, suckback, undercut, and overlap are defects that occur in weld joints. Cracks compromise structural integrity by creating a path for fracture. Undercut is a groove at the weld toe that reduces the weld’s throat, weakening the joint. Overlap happens when weld metal extends beyond the joint without fusing to the base metal, which can create stress concentrations. Suck-back refers to molten weld metal pulling back as it solidifies, leading to poor filling or crater formation. These issues are characteristic of welded assemblies, i.e., weldments, rather than castings, forgings, or extrusions, which have different typical defects associated with their respective manufacturing processes.