Can anyone explain the markings on this case back, Google is stumped.

Specifically the:

OE-15375 numerals

Thank you

Richard,

That should be a really nice watch.

Below is a table from Chapter 1 General Information out of the TM9

ORDNANCE
DEPARTMENT
MARKINGS.
a. The Ordnance Department numbers each watch with letters which signify the grade of the watch and the service to which it is issued, followed by the ordnance serial number marked plainly on the exterior back of the case. This serial number is the only number referred to in identifying an ordnance timepiece. Each watch is identified by the following ordnance code markings:

(1) For new manufacture:
(a) OA for 7- to 9-jewel pocket watches.
(b) OB for 15- to 17-jewel pocket watches.
(c) OC for 7- to 9-jewel wrist watches.
(d) OD for 15-to 17-jewel wrist watches.
(e) OE for 21-jewel railroad grade pocket watches.
(f) OF for 15- to 17-jewel wrist watches (waterproof case).
(g) OFA for 15- to 16-jewel wrist watch, waterproof case, Air Corps (Navigation, Type A-11, substitute standard).
(h) OG for 7- to 9-jewel wrist watch (waterproof case).
(i) OS for stop watch.

(2) For manufacture prior to 12 November 1940. (Identifica tion to be added at time of repair on watches not previously marked.)
(a) OW for 7- to 9-jewel pocket watches.
(b) OX for 15- to 17-jewel pocket watches.
(c) OY for 7-to 9-jewel wrist watches.
(d) OZ for 15- to 17-jewel wrist watches.

Hi Richard.

The US Army Ordnance Department required watch manufacturers to use code letters to identify the grade of the watch movement that was inside of the watch when they delivered it to the Army under their contracts. These codes are:

For new manufacture after November, 1940

OA 7 to 9 jewel pocket watches
OB 15 to 17 jewel pocket watches
OC 7 to 9 jewel wristwatches
OD 15 to 17 jewel wristwatches
OE 21 jewel railroad grade pocket watch
OF 15 to 17 jewel wristwatch in a waterproof case
OFA 15 to 17 jewel wristwatch, waterproof case, Army Air Corps navigation grade, substitute for A-11 watches
OG 7 to 9 jewel wristwatch in a waterproof case
OS Stopwatch

For re-manufactured/repaired watches that were delivered before the markings were required, i.e. November 1940 the following markings were to be added at time of re-manufacture/repair:

OW 7 to 9 jewel pocket watch
OX 15 to 17 jewel pocket watch
OY 7 to 9 jewel wristwatch
OZ 15 to 17 jewel wristwatch


Paul just beat me to the response by 1 minute. He must have faster typing skills than me. Oh well

Any idea on the numerals that follows the OE?


Is this WWII or Korean era designations?

I have one also with Ordnance Dept USA OE-782


Both have Hamilton 992B movements, one is marked U.S. Army(OE-782)

The numerals following the two letter movement code are the serial number. These would be WW2 era though I am not certain when they stopped these markings so it could be post war.

Thank you Jim and Paul.

That fits, the low serial on the outside pairs with a low number on the movement.

These are US Army serial numbers and they go from low to high on each of the watch types, starting over with each type - they are not one consecutive set of serials across all of the types.

Also, that is good to hear that the relative serial numbers of the Army ones vs. the manufacturer ones correlate well for their age. Back when these were in regular use in the Army there were watch repair stations within the Army and they did not care much if they put the same movement back into the same case, or whether they put a new movement into an old case. These were simply tools to them that were made to be repaired and put back into service.