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WWII A-11 cases: what exactly was basemetal? "Click" to Login or Register 
Hello All,

I've been wondering about this for a long time, and figured this forum might be the right place to ask.

What exactly was the basemetal used in World War II A-11 watch cases?

I have two examples of WWII A-11 cases in my collection: one made by Star, and one made by Keystone. The Keystone case is made of a metal that almost looks like brass, but is too subdued. I have heard that cases were made of some kind of nickel-alloy. The screw on back appears to be a different metal, possibly stainless, as it did not corrode like the rest of the case.

So, what were WWII A-11 cases made of, cupro-nickel? German silver with high copper content?

Also, what were the case backs made of?

Thanks, hope you all can shed some light on this!
Posts: 15 | Location: Northern Arkansas in the USA | Registered: September 30, 2009
IHC Member 1101
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Picture of Steve Middlesworth

As David Abbe once discribed it:

"Base Metal". This was a "Heat" (or alloying) of Aluminum, Copper, Magnesium, Silicon, and Zinc to create a durable and highly corrosion resistant watch case alloy without need for ANY plating! Base Metal proved to be fully what everyone expected for this job. I think that some cases were Chrome plated, but that was more of a "feel good" thing than for any real purpose.

Posts: 1980 | Location: Kentucky in the USA | Registered: March 18, 2008
Thanks for the answer, that makes a lot of sense! My A-11 case looks like brass under the plating, but when scraped in an un-noticeable place reveals a more silverish color. The copper could explain the brassy look old tarnished and corroded cases assume over time.

Any idea of the amounts of the different metals used? I would imagine that Zinc, Aluminum, and Copper, in that order, comprised the greater parts.
Posts: 15 | Location: Northern Arkansas in the USA | Registered: September 30, 2009
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