Use a simple compass method to screen whether a mechanical watch may be magnetised — then interpret the result and decide the next step.
Demagnetize with a proper watch demagnetizer and re-check timing. Avoid resting the watch on strong magnets afterward.
• Keep phones away while testing
• Use a basic magnetic compass, not a busy phone compass app if possible
• Repeat the test once to confirm the reaction
How can I check if my watch is magnetized? A simple compass screen plus timing behaviour is a practical first check.
What does a magnetized watch do? It often runs fast or erratically until demagnetized.
If the compass does not move, is the watch safe? Probably lower concern, but not absolute proof of zero magnetism.
Can I demagnetize it myself? Many owners use a proper demagnetizer successfully. Follow correct technique and re-test timing afterward.