During inspection, what should the root bead of a single-V-butt weld be checked for?

• A. Excess weld metal height
• B. Lack of root penetration
• C. Correct weld travel angle
• D. Surface finish quality

Answer: (B)

The root bead of a single-V-butt weld is crucial because it forms the initial connection between the two pieces of metal being joined. Checking for lack of root penetration is vital since adequate penetration ensures that the weld is strong and capable of supporting the structural integrity of the joint. Insufficient penetration may lead to a weak bond, creating a point of failure under stress or load, which can compromise the entire structure.

In weld inspection, factors such as excess weld metal height, weld travel angle, and surface finish quality are also important but do not specifically pertain to the root bead. Instead, they address other aspects of weld quality. For instance, while excess weld metal height may relate to geometry or appearance, it does not directly impact the root connection as significantly as penetration does. Similarly, weld travel angle concerns the technique during welding, but it is not specific to the evaluation of the root bead itself. Finally, surface finish quality pertains to the overall aesthetic and surface characteristics of the weld rather than the critical integrity of the root penetration. Therefore, focusing the inspection on root penetration is essential for ensuring a robust and defect-free weld.