Definition
To remove the residual magnetic field from a ferromagnetic part or tool. In aviation maintenance, demagnetizing is performed after magnetic particle inspection so the part does not retain magnetism that could attract metal debris, disturb nearby instruments, or interfere with the aircraft compass.
Plain English
Taking the magnetism out of a metal part so it no longer acts like a magnet.
Context Anchor
Seen in aircraft maintenance, especially around magnetic compass checks, compass errors, and tools or metal parts used near the cockpit.
Derivation
From the prefix de- (Latin, meaning 'remove' or 'reverse') plus magnetize. Literally 'to undo the magnetizing.' The prefix tells you the action is being reversed, which is exactly what the process does.
Why Pilots Care
Magnetic tools can cause compass errors and navigation inaccuracies if not treated.
Intuition Check
Demagnetize does not mean to remove a magnet from the airplane. It means to remove unwanted magnetism from an object so it no longer affects nearby magnetic equipment.
Example Sentence 1
After the magnetic particle inspection, the technician demagnetized the crankshaft before reinstalling it.
Example Sentence 2
After welding a bracket, the technician demagnetized it to prevent compass deviation.