Does Impact Magnetize a Watch?

Most recent answer: 07/10/2015

Q:
I am a watch maker , seem like mechanical watches nowadays get magnetise very easily .Can heavy impact cause the parts in a watch to be magnetise ? All watch parts had side shakes after assembly , is that the cause that they are touching each other when impact is produce and so it produces magnetism ?
- Howard Sew (age 43)
Singapore
A:

Impact by itself won't magnetize a watch. However, it can make it easy for the magnetic domains to realign. Impact tends to de-magnetize something that's already magnetized. Starting with something that's not magnetized, impact could help it magnetize if there's already a magnetic field around. Since the Earth's field is small, I wouldn't expect that to cause much magnetization. Are there other magnets around?

Mike W.


(published on 07/10/2015)