In a multi-pass weld, which pass finishes the weld and provides surface appearance?

• A. Root pass.
• B. Fill pass.
• C. Cap pass.
• D. Tie-in pass.

Answer: (C)

The final pass, called the cap pass, finishes the weld and provides surface appearance. After the root pass establishes the weld at the joint root and fill passes bring the weld up to its full height, the cap pass sits on top to shape the crown and create a smooth, visually uniform surface. This last layer controls the weld’s final contour and cosmetic quality, which is what inspectors and service conditions rely on. If the cap isn’t done properly, the surface can be uneven or undercut, and the weld may not meet aesthetic or protective requirements.