AWS Certified Welding Inspector — FundamentalsInspector Duties and ResponsibilitiesEasy
During a post-weld visual inspection of a structural steel weld, a CWI observes a continuous, shallow groove along the toe of the weld that is parallel to the weld axis. The groove is approximately 1/32 inch (0.8 mm) deep and does not extend beyond the base metal. What discontinuity is the CWI observing?
- AUndercut
- BUnderfill
- CCrater crack
- DOverlap
Show answer & explanationAnswer & explanation
Correct answer: A. Undercut
Undercut is a groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal. The description of a 'continuous, shallow groove along the toe of the weld' perfectly matches the definition of undercut.
Why the other options are wrong
- B. Underfill is a depression on the weld face or root surface extending below the adjacent surface of the base metal, not specifically a groove along the toe.
- C. A crater crack is a crack in the crater of a weld, not a continuous groove along the toe.
- D. Overlap is the protrusion of weld metal beyond the toe or root of the weld, which is the opposite of a groove.
Undercut
Undercut is a groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal.
- Located at the weld toe or root.
- A groove in the base metal.
- Left unfilled by weld metal.
Memory trick: A 'cut' at the 'toe' is an 'undercut'.