What does an "M" on the main plate mean?

Franco · Nov 9, 2022

Good morning
on an Italian watch forum there has been the question for the meaning of an M on the main plate of a 30T2 SC.
No Inscriptions at the bck for military assignments, reference is 2320-2 , movement serial for 1944-45.
Does not look just carved in - probably using a metal letter punch.
Anybody knows its meaning?
Franco

Mark020 · Nov 9, 2022

That it is 'normal' metal and not gold

Franco · Nov 9, 2022

Mark020
That it is 'normal' metal and not gold

What do you mean by that? Of course is not gold. Thousands of other 30T2s of the same "deuxe" finish - double copper plating on beryllium bronze (an alloy of beryllium and 2.25% copper), do not have the "M". The M cannot mean that is metal and not gold, or all of them should have it.

Or if it does, it must be from some vwry specific market.

mac_omega · Nov 9, 2022

If I recon correctly its related to the case metal and is often found on movements with steel cases and other non-noble metals. Yann (@Tire-comedon) probably knows better, I think it was him who mentioned this to me... maybe only used on watches sold to France?

BTW the copper coloured galvanic coating on movements of this age is rose gold and the plates are just made of brass - no beryllium nor beryllium bronze was used for the plates.

Franco · Nov 9, 2022

Regarding the finish, I thought I was quoting what you told me once, regarding the RGs. But must be a wrong recollection.

tamura · Nov 9, 2022

https://omegaforums.net/threads/meaning-of-a-small-‘m’-stamped-into-the-movement-bridges.52299/

Mark020 · Nov 9, 2022

Franco
What do you mean by that? Of course is not gold

No that is what the M says 😁

Franco · Nov 10, 2022

Thanks to all replies, best. f

OllieOnTheRocks · Nov 12, 2022

From my experience, an M is found on 30T2 that have "fab Suisse" on the dial, so sold in France. So that the companies that assembled the watches in France knew whether the watch (and dial) was going into a gold, or Metal (steel) case. Gold ones, I believe were made locally to reduce the import costs, and this was the purpose of this marking. If it doesn't have 'fab Suisse' on the dial, I would personally consider that a red flag, and consider it is probably a franken watch. All of my fab Suisse 30T2s have the M on the movement.

X350 XJR · Nov 15, 2022

Don't know it this will confuse further or clarify.

Fab. Suisse dialed Pierce with M marked movement. Seems to have eventually been exported to the USA having the PXA import code hand engraved on the movement.