Definition
The deposit of fused metal left on a joint after welding. The bead is the visible ridge of solidified weld material that joins two pieces of metal together, and its appearance, width, and uniformity are used to judge the quality of the weld.
Plain English
The line of melted-and-resolidified metal that you can see along a finished weld. It is the seam the welder leaves behind when joining two pieces of metal.
Context Anchor
Seen in aircraft maintenance discussions, especially around welded steel tube structures, engine mounts, exhaust parts, and repair inspections.
Derivation
Bead originally meant a small rounded shape, like a bead on a necklace. A weld bead is named for its rounded, ridge-like profile running along the joint.
Why Pilots Care
On aircraft with welded steel-tube structures, the quality of the weld bead is a direct indicator of structural integrity. A clean, even bead suggests a sound weld; a rough, cracked, or undercut bead can be a sign of a weak joint that may fail under load.
Analogy
It is a little like the raised line of caulk left along a seam, except a weld bead is metal and is part of the joined structure.
Intuition Check
A weld bead is not just extra metal sitting on top of a joint. It is the visible result of the metal being joined and is one clue used to judge whether the weld was made properly.
Example Sentence 1
During the annual inspection, the mechanic checked each weld bead on the engine mount for cracks or porosity.
Example Sentence 2
A smooth, even weld bead shows the technician used the correct travel speed and heat setting.