During visual inspections, what does an undercut refer to?

An undercut refers specifically to a groove that is melted into the base metal adjacent to the weld. This groove can occur during the welding process when excessive heat is applied, causing the edges of the base metal to melt away, leaving a depression that can compromise the integrity and strength of the joint. This characteristic makes undercut a critical factor to identify during visual inspections, as it can potentially lead to failure under stress due to weakened areas in the weld joint.

In visual inspections, both the correct identification of undercut and an understanding of how it relates to the overall integrity of the welded structure are essential. Recognizing such features is important for ensuring compliance with the standards set forth in welding specifications, which require welds to maintain specific geometries without unacceptable deviations that could affect their performance.