What do you call a groove in the parent metal at the toe of a weld?

What do you call a groove in the parent metal at the toe of a weld?

• A. Undercut
• B. Groove weld
• C. Root crack
• D. Crazing

Answer: (A)

In welding, an undercut is a groove melted into the base metal along the weld toe and not filled by weld metal. This creates a notch at the edge where the weld meets the base metal, thinning the section and concentrating stresses, which can lead to cracking under load. A groove weld describes the joint type where a groove is prepped to be filled with weld metal, not a defect at the toe itself. A root crack would be a crack at the bottom of the weld, not simply a groove along the toe. Crazing isn’t the term used for this weld feature. So, the groove in the parent metal at the weld toe is called an undercut.

In welding, an undercut is a groove melted into the base metal along the weld toe and not filled by weld metal. This creates a notch at the edge where the weld meets the base metal, thinning the section and concentrating stresses, which can lead to cracking under load. A groove weld describes the joint type where a groove is prepped to be filled with weld metal, not a defect at the toe itself. A root crack would be a crack at the bottom of the weld, not simply a groove along the toe. Crazing isn’t the term used for this weld feature. So, the groove in the parent metal at the weld toe is called an undercut.