🔍 Key Concepts

• Butt joint weld quality – what a proper finished weld should look like in profile • The meaning of overlap and undercut at the toe of the weld and why each is considered a defect • Basic goal of structural welding: smooth transfer of load through the joint without stress‑raisers

💭 Think About

• Think about whether either overlap or undercut adds strength, or if they create weak points where cracks can start. • Picture the ideal weld cross‑section on a single‑V butt joint: how should the weld metal blend into the base metal on both sides? • Ask yourself which combination of conditions describes a weld that is free of common defects rather than one that would need to be ground out and re‑welded.

✅ Before You Answer

• Be clear on definitions: overlap (weld metal lying on base without proper fusion) vs undercut (groove melted into base metal left unfilled). • Decide whether a good quality weld is expected to have any known weld discontinuities/defects, or to be free of them. • Mentally eliminate any option that explicitly requires a known weld defect to be present as a characteristic of a “good” weld.