Definition
A form of electric resistance welding in which two overlapping pieces of sheet metal are pressed together between two copper electrodes, and a strong electrical current is passed through them for a brief moment. The resistance of the metal to the current generates enough heat to fuse the two pieces together at that single spot, without the use of filler material.
Plain English
A way of joining two thin pieces of metal by squeezing them between two electrodes and passing a quick burst of electricity through them. The metal heats up just enough at that one point to melt and fuse together, leaving a small round weld.
Context Anchor
Seen in aircraft maintenance and airframe construction, especially where thin metal parts are joined without making one long continuous weld.
Derivation
Spot' refers to the small, localized point where the weld occurs, as opposed to a continuous seam. The name simply describes what the weld looks like: a single spot of fused metal.
Why Pilots Care
A pilot may see spot welding mentioned in maintenance records or inspection findings. A failed spot weld can let a panel, bracket, or shield loosen, so it matters for the aircraft’s condition and airworthiness.
Intuition Check
Spot welding does not mean any small weld made by hand. Here, it means a specific electric-resistance process that bonds metal at small clamped points.
Example Sentence 1
The firewall on the aircraft was assembled using spot welding to join the stainless steel panels.
Example Sentence 2
Factory workers joined the aluminum ribs to the wing skin with spot welding before final assembly.