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!

Nathen,

As David Abbe once discribed it:

quote:

"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.

Steve

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.