Weld Seam

The weld seam represents the visible boundary where the molten filler metal solidified, creating the fusion line between base and deposited material; seam appearance provides the first visual clue to overall weld quality. A properly executed seam displays uniform bead width, consistent reinforcement height, smooth underbead profile, and freedom from spatter or visible defects like cracks, cold laps, or roll-over.

Visual inspection of the weld seam is the first line of quality control, performed by the welder immediately after cooling and subsequently verified by supervisory personnel before the assembly moves to post-weld operations like finishing and painting. On applications requiring weld inspection, seam geometry is documented photographically and cross-referenced to the applicable welding procedure specification to ensure dimensional compliance before nondestructive testing is performed on sample welds or suspect areas.