pereztroika
60
AM = Anti Magnetic
I am pretty sure, but not Antimagentic as already stated on the cb referring to the movement protection against magnetism by means of an antimagnetic soft iron cover absorbing magnetism. AM refers to the non-magnetic signature of the whole watch. The case is probably made of steel 310, as required in MIL-W-22176A. This was necessary to avoid setting off mines with magnetic trigger mechanisms. These mines were activated by ship hulls, etc., so having a magnetic watch on the wrist was dangerous. Btw, 316L and 904L are non-magnetic as well. Please check whether older FFs have magnetic cases.
Looking at this whole thing through this lense, I believe the AM watches came first, then the rejected bronze batch, and finally the TR900, which features the μ (Mu, magnetic permeability) symbol on the back, the later equivalent to AM imo.
Cheers
Jose
Vintage Blancpain Fifty Fathoms Bronze Milspec.
An eternal pleasure, this watch: An old photo, but the watch is still with me. Best, Nicolas ...
One stunning example
I'm so used to waterproof dive watches it would require a tremendous amount of concentration to remember to remove my watch before taking a dip, especially pool side!
Radium bezel?
Does this one also have a radium bezel in combination with a tritium dial? Cheers Jose
AM = Anti Magnetic
I am pretty sure, but not Antimagentic as already stated on the cb referring to the movement protection against magnetism by means of an antimagnetic soft iron cover absorbing magnetism. AM refers to the non-magnetic signature of the whole watch. The case...
Aaah, I neglected the idea of AM as Anti Magnetic because to me, it didn't make sense to " double " this mention on the case back... Now, as for the chronology,
I would rather say that the TR went first, in 1964 and in 1966, then the AM and the rejected Bronze ( on this last one, we agree ). For me, but it is just a guess as I didn't find any documentation to prove it, the AM came just after the TR. Same case, pr...
AM radium or tritium?
Most pictures online are photographed in a way that doesn't show whether it's Swiss or T Swiss T. Cheers Jose
That is AM 57...
if I am not mistaken. How about AM 38 and 103? With military watches, dials were often replaced. First, radium dials lasted only 3 to 5 years. When they switched to only marginally radioactive compounds like tritium, dials were replaced again, and of cour...
No, I meant that a T Swiss T dial could well hide a radium dial...
103, 97, and some other AM with erased numbers have the same dial. 103: 97: Unknown number: ...
The Milspec AM 38 is still in my collection
No. The Milspec AM 38 is still in my collection; it was featured in the 2010 Tribute to Fifty Fathoms exhibition.
Nah, I don't think so
A 'T Swiss T' designated dial shouldn't have radium. I think that would have been illegal anyway, as radium was banned for the Swiss watch industry in 1964. If there is strong radiation, it must come from the bezel. The only way to find out, is to take th...
AM.....
For me, AM means in French "amagnétique" “non-magnetic.” AM also used by Patek Philippe for ref 3417 In chronological order, I think TR 900, then AM, and finally the so-called “Bronze.”
Aren't U.S. Navy bronze dials radium?
There is no mention of tritium on those. Btw, is this a known bronze example: www.instagram.com / Cheers Jose
T< 25 Mc for the Bronze Milspec.
Swiss for the US Navy Dial. ( Forget the insert, this is not the good one on this US NAVY, AFAIK ). ...