Definition
A group of welding processes that join metal parts by melting them with the intense heat produced by an electric arc struck between an electrode and the workpiece. A filler metal is usually added to the molten pool, which solidifies to form a continuous metallurgical bond between the parts.
Plain English
A way of joining metal pieces by using a powerful electric spark to melt them together, often with extra metal added to fill the joint as it cools and hardens.
Context Anchor
Seen in aircraft maintenance and repair discussions, especially when reading about approved repairs to metal structures, engine mounts, exhaust parts, or shop procedures.
Derivation
‘Arc’ comes from the Latin arcus meaning ‘bow’ — the curved shape of the visible electrical discharge between the electrode and the metal. ‘Welding’ comes from an Old English root meaning to join or unite by heating. So the term literally means ‘joining metal using a bow-shaped electric flame.’
Why Pilots Care
Many aircraft structural components — engine mounts, landing gear fittings, steel-tube fuselages — are arc welded. Pilots performing preflight inspections need to recognize welded joints and check them for cracks, since a failed weld in a critical structure can have serious consequences.
Intuition Check
Arc welding does not mean welding in a curved shape. Here, arc means an electrical arc used as the heat source.
Example Sentence 1
The mechanic used arc welding to repair a cracked engine mount on the steel-tube fuselage.
Example Sentence 2
Aircraft technicians must follow approved procedures when arc welding aluminum airframe parts.