Magnetism refers to the influence of magnetic fields on the accuracy and functionality of a watch, often requiring anti-magnetic materials or designs to mitigate its effects.
Magnetic fields cause steel components—primarily the hairspring—to become magnetized, making coils attract each other and reducing the effective spring length. This increases oscillation frequency, causing the watch to run fast, sometimes by minutes per day. Even brief exposure to strong magnets (bag closures, MRI machines, speaker magnets, electric motor fields) can significantly affect accuracy.
Common sources include smartphone and tablet magnetic cases or closures, laptop magnetic closures, handbag magnetic clasps, refrigerator magnets, electric motors in appliances, MRI machines (avoid entirely), airport security equipment, and even some induction cooktops. Modern life exposes watches to frequent low-level magnetic fields that cumulatively affect non-protected movements over time.
Yes, demagnetization is quick and inexpensive at any watch service center. A watchmaker uses an AC demagnetizer (bulk eraser) that passes the watch through an alternating magnetic field that gradually decreases, returning components to their neutral state. The process takes under a minute and restores normal accuracy immediately. No disassembly is required. If accuracy problems persist afterward, other issues—worn parts or lubrication—may be the real cause.