Are there any IWC pilots watches antimagnetic up to 80,000 A/m?

Hi Everyone!

Multiple posts in the forum archives seem to point at the fact that IWC pilots watches have an anti magnetic resistance of 40,000 A/m max. But I found this piece of information in the current collection section of the portal dedicated to the Mark VII:

"Depending on the model in question, the protection provided – of up to 80,000 amperes per metre – exceeds the Swiss norm for antimagnetic watches by more than sixteenfold."

Here's the link:

www.iwc.com/en/collection/pilots/IW3265/

I wonder which are these pilots references that have this high magnetic resistance...would the (now discontinued) 3799 be one of them? or did the older doppel 3713 have a 80,000 A/m resistance?

Thanks in advance for any information on this....

Best Regards,

Sumit

An anti-magnetic watch should withstand a magnetic field of 4800 A/m without stop ticking and without a deviation in accuracy of +/- 30 seconds per day. This is determined by DIN 8309 and ISO 764. When a watch is protected by a soft iron case the magnetic flux will not enter the into the movement but "flow" around it. The IWC pilot watches, starting with the famous cal. 89 Mark 11, have such case and around the soft iron inner case is an outer steel case.
A watch with such a double case can withstand a magnetic field "up to 80.000 A/m)", meaning that not every produced watch will exacly meet the limit of 80.000 A/m.
This is not necessary as a pilots watch will not be used in circumstances where such strong magnetic fields exist.
However, IWC made 2 watches : ref. 3508 and ref. 3519 AMAG BUND ( both not pilot watches), that could resist a magnetic field up to 500.000 A/m. With these 2 watches IWC holds the world record of most resistant watches against magnetic flux.
Kind regards,
Adrian,
(alwaysiwc).

Adrian, great knowledge share - thank you!

Adrian, I don't want to tout the Rx name here, and I have never been Rx fan, but doesn't their Milgauss version "beat" the IWC "world record of most resistant watches against magnetic flux"? As far as I know the Milgauss can handle 1.000 Gauss which equals 1.000.000 A/m (1 Gauss = 1.000 A/m). Just want to make sure I have my facts right :-)

I am nut shure if A/m and Gs are comparable just by a factor. I think they do not describe exactly teh same. (1 Gs = 1000 A/m ? I to really found this numbers)

Best regards

Ralph

Adrian,I think the new Omega Seamaster Aqua Terra at 15,000 Gauss antimagnetic might break the record. But --frankly-- who cares? The numbers exceed all practical purposes and really are used for advertising.

Fully agree Michael :-)

Check this link though for the conversion between SI and cgs units:
www-d0.fnal.gov/hardware/cal/lvps_info/engineering/mag_conv.htm

Thanks gentlemen for these insights! And thanks Adrian for that knowledge! I found this on the net on the AMAG Bund:

milspectime.com/wp-content/uploads/2013/04/IWC-Bund-Watches_HJ_Adrian1.pdf

So is it possible that the Top Gun ceramic doppel 3799 is antimagnetic to 80,000 A/m?

Best Regards!

Sumit

Very interesting, thank you.

The magnetic fields inside a cockpit of an WW II airplane, or of the early jet age, were generated by the communication and navigation equipments, radar, etc. These magnetic fields were stronger than those generated by the equivalent equipment in today's airplanes, but none justifies an amagnetic capability of 500,000A/m.
Pilot watches of the past needed to be amagnetic because the crew relied on astronavigation to reach their destination and the latitude can only be known exactly if the exact time is known. A deviation of a couple of seconds, from magnetization, would result in missing the target destination.
As Michael said, its just advertizing, much like a watch being waterproof to 2,000 meters. When was the last time anyone had to interrupt a dive because he/she reached 1,999 meters and did not want to proceed not to damage the diving watch?

I agree...magnetism is very rarely a problem nowadays. Still, I was having this academic curiosity regarding the anti magnetic capabilities of my 3799 since it has a soft iron core. Its like knowing the top speed of a car - you are never gonna go that fast! Would any of the experts know if the 3799 falls in the 80,000 A/m bracket?

I wonder how they measure the magnetic resistance of a watch. Is it like inflicting progressive magnetic strength or power to a watch and waiting until it breaks down? Can you measure it yourself with not too expensive equipment? Or is the value presented an estimate based on the kind of antimagnetic cage provided?

Kind regards,
Paul

That is good question. However, for standard movements we can derive a clue from the thickness of dials. By standard movements I refer to those that do not possess any special anti-magnetic properties over 4,800 A/m.

Between two such watches with soft iron cores, the movement ring and the back cover being constant, it is the thickness of their soft iron dials that will differentiate their individual magnetic resistance capabilities. In this case a soft iron dial thickness of 0.9mm imparts a protection of upto 80,000 A/m. Here's a good link on this subject:

home.watchprosite.com/?show=nblog.post&ti=383432

Now if only I knew what the thickness of the 3799's, 3778's and the 3713's dials were, i would be able to make a rough comparison of their individual magnetic resistance (neglecting the thickness of the back cover and the movement rings)...

Best Regards,

Sumit

One additional point, Adrian

Both watches are ultra high resistent against magnetic fields, but nevertheless they have totally different tasks.

The 500.000 A/m is just magnetic resistent but some parts inside react on magnetic fields. It has still magnetical potential !

If you put it into a small wooden boat, you can control the boat with a strong permanent magnet.

The AMAG is magnetic resistent too, but it has NOT any magnetic part inside. It has NO magnetical potential !

No chance, to control the same boat with an AMAG on board !

I would not defuse a mine, with a 500.000 A/m on my wrist !!!!!!!

Now we need someone who will check it :-)

Regards

Heiko

Sorry --no, it does not.

Some confusion on the parameters used for "magnetic influence" can trouble the understanding of "anti-magnetic" watches. The term anti-magnetic" is describing a condition that does not exist. Most metals have more or less magnetic properties : iron, nickel and cobalt are highly magnetic. Copper and platinum are not influenced by magnetic fields. If one woud make a complete watch from platinum, titan, copper, berylium and some other metals or alloys, the watch would not be anti-magnetic but dia-magnetic : zero influence by a magnetic field. To express magnetic "activity" several para meters are used such as Ampère/meter or Oersted. Both parameters are used to express the strength of a magnetic field. 4800 A/m equals 60000 Oersted( I am avoiding dots and comma's as there significance is different between the US and Europe): 1,000 $ is a lot of money in the US, but only one dollar in Europe; 1.000 Euro is a lot of money in Europe, but only one Euro in the US.
Than there are the parameters for magnetic flow or better flux. These parameters indicate how much "energy" is passing in time and area. The flux is expressed in Gauss or Tesla. Often these 4 parameters are used mutually and a table is used to read the proportion.
So 1 Tesla equals 1000 Gauss equals 10 milion Oersted equals 800 thousand A/m. The Rolex Milgauss can be compared to the best a-magnetic watches of IWC.
The AMAG BUND as described by hebe was not designed to withstand strong magnetic fields, but to not disturb weak magnetic fields. The sea mines used world wide from about 1930-1960 had an ingenious ignition system. Once dropped in a harbour, the mine adjusted itself to the earth magnetic field of the local area. This field is very weak but differs over the globe.
Once set, the mine would explode if the magnetic field around the mine was disturbed. This happened of course if a steel ship would sail above it. But it could also happen if a mine sweeper (Minentaucher) would approach the mine, to demolish it. Any magnetic metal (steel, nickel etc.) had to be avoided, meaning that the mine sweepers of the German Navy had an equipment, without any iron or steel, including their watch ...the titan Ocean AMAG Bund. If the diver would have used ref. 3508, the mine would explode. This watch had a soft iron inner case and a nearly a-magnetic steel alloy outer case. This would lead to a peculiar situation. The watch would by no means be influenced by the mine, but the watch in reverse would trigger the mine ignition....boom!
Kind regards,
Adrian,
(alwaysiwc).

Thank you very much, Adrian, this really was new to me, very interesting! Now I guess that for us, watch lovers, the important issue is if the watch can be disturbed by a magnetic field (or something like that?), and that the property to let a mine explode or not comes second. Do you have an idea how the degree of avoidance power of magnetic damage of the watch is determined and measured? I really am not sure anymore how to describe this all, but I feel there is a possibility here to learn about this: thank you or others for an answer.

Kind regards,
Paul

Thanks a lot Adrian and Heiko for that detailed information!