What magnetic field can watches take?

[submorstua]

I know there are many threads asking if magnets are "a problem" for Rolex watches. However, I'm wondering if there is any source of information on what watches can actually take in terms of magnetic force before they run into issues.

I work in ultra high-field MRI research and regularly encounter field strengths of 70,000 Gauss (7 Tesla human scanners) and occasionally encounter 94,000 to 150,000 Gauss scanners. Obviously there's no mechanical watch (or any watch for that matter) that can be close to these scanners, as the opening of the bore still has a static field of around 35,000 Gauss (in the 7T case). Taking a mechanical watch in an MRI magnet room is unsafe for the watch, the wearer, the machine, and anyone near you, so I want to make it clear that I'm not asking whether any watches can go in a scanner.

That said, I am curious about how much a watch can actually take. I know that a few modern anti-magnetic watches combat magnetic fields (Milgauss, Omega >15,000, etc.), but for us owners of the rest, what field can they take, or has this been studied? Of course the orientation of the watch to the magnetic field matters for this question, but to keep it simple we'll just assume it doesn't.

I have a few clues, but I'm wondering if anyone knows more about the subject. In the following I'll try to stick to Gauss measures. First, depending on where in the world you live, the magnetic field that you encounter just wandering around outside is between 0.25 and 0.65 Gauss. Okay, so we know that's fine. Someone opened our magnet room's shielded door recently during testing and I inadvertently walked through a ~5 to 6 Gauss field, and my DateJust wasn't affected at all. This doesn't surprise me as I've heard that the inside of a refrigerator can reach almost that much and I'm sure a lot of us are willing to make dinner with our watches on...

Here are some magnetic strengths of a few objects people might come in contact with while wearing their watches (and some not so common ones that are interesting for Milgauss fans):
1. Typical refrigerator magnet - 50 Gauss
2. Neodymium magnet (computer hard drive) - up to 12,500 Gauss
2. Coil gap of a typical loudspeaker magnet - 10,000 Gauss or greater
3. CERN magnets surrounding the Compact Muon Solenoid - 40,000 Gauss
4. CERN magnets surrounding the Large Hadron Collider - 80,000 Gauss

So this isn't a lot to go on, and if I was really daring I'd test it out myself. Taking my watch to a watchmaker all the time when I accidentally magnetize is doesn't sound that fun to me though. Has anyone who owns a demagnetizer tested at what point their watch no longer runs well? If so, I'd love to hear about it.

[submorstua]

After writing my initial post today, I came across an article on Hodinkee talking about how an Omega test watch actually withstood 16T (160,000 Gauss):

https://www.hodinkee.com/articles/om...bit-aqua-terra

That's pretty amazing, although I'm not sure I understand naming it the >15,000 if it can actually withstand 10x that...

I just wish Rolex would throw their hat in the ring. I know everyone's got different hopes for Basel 2017 - this is mine. I would absolutely love to see a rotatable bezel on the Milgauss with a red color theme again (basically bring back the 6541)!

[Etschell]

Way to technical. Mechanical watches can take a beating however just ask neil armstrong.

[DramaTurtle]

If you're looking for anti-magnetic, I believe your best bet would be Omega's Aqua Terra line or an IWC Ingenieur.

If you're looking for a beater, check out Ball's anti-magnetic offerings.

[Friar]

Good article on Hodinkee comparing Milgauss and Omega--

https://www.hodinkee.com/articles/a-...odymium-magnet