Definition
A solid copper wire coated with a thin layer of insulating enamel or varnish, used to wind the coils of electrical components such as motors, generators, transformers, relays, and magnetos. The thin insulation allows many turns of wire to be packed tightly into a small space while keeping each turn electrically separated from its neighbors.
Plain English
Thin copper wire with a varnish-like coating, used to make the tightly wound coils inside electrical parts. The coating keeps the wire from short-circuiting against itself when it is wound into many close turns.
Context Anchor
Seen in aircraft electrical and ignition system discussions, especially when describing coils, generators, alternators, relays, and other wound electrical parts.
Derivation
Called magnet wire because its main job is to create magnetic fields. When current flows through many tight turns of this wire, the coil becomes an electromagnet -- the basis of how motors, generators, and magnetos work.
Why Pilots Care
Magnet wire forms the windings in magnetos, alternators, and starter motors; a failure here can cause loss of ignition or electrical power, directly affecting flight safety and reliability.
Intuition Check
Do not read “magnet wire” as wire that is already magnetic. Here it means insulated wire used to build a coil that can create magnetism when electrical current flows through it.
Example Sentence 1
When the magneto coil failed, the technician found that the magnet wire inside had broken down where the insulation had overheated.
Example Sentence 2
The alternator stator was rewound with magnet wire that matched the original insulation class to prevent overheating under full electrical load.