Can a watch be left fully wound indefinitely?

Yes. Modern mainsprings include slipping bridles that prevent over-tensioning. Storing a watch fully wound is the recommended state for keeping lubricants properly distributed across the gear train.

Will airport security harm my watch?

No. X-ray scanners (both carry-on and checked) do not magnetise watches. Walk-through metal detectors and millimetre-wave body scanners are also safe. The only routine risk is magnetism from speakers, MRI machines, and certain induction cooktops.

Watch Ownership

Winding, Storage, and Watch Winders

Long-term storage of mechanical watches involves more nuance than most owners realise. The right approach depends on whether the watch has a perpetual calendar, whether it's a daily wearer, and how often you plan to rotate through it.

By Ira Zoot

Reviewed against editorial standards Last updated April 26, 2026 Subject-matter reviewed

When to use a winder

Winders are most useful for watches with annual or perpetual calendars, where re-setting the date display is time-consuming and risks damage if performed near midnight. For simple time-and-date watches, hand-winding when you next put the watch on is generally preferable - it puts less continuous wear on the mainspring and reverser system.

Choosing a winder

Specifications to verify: turns-per-day (TPD) range matched to your specific calibre (most modern automatics need 650–950 TPD), bidirectional rotation, and program intervals that include rest periods. Quality winders use brushless motors for low electromagnetic emission; cheap winders can magnetise the balance spring.

Static storage

Watches not on a winder should be stored fully wound (to keep lubricants distributed) in a stable environment: room temperature, low humidity, away from speakers, MRI machines, induction cooktops, and other strong magnetic sources.

Travel storage

Use a watch roll or padded pouch - never loose in a bag. For air travel, keep watches in carry-on; checked baggage exposes movements to extreme temperatures and impact. TSA scanners are X-ray and do not magnetise watches.