HI,
Check Evolution Of 4992B and 3992B page 1 IT
will give you a good idea.Lots of good info.here.
Hub.

THE 4992B MOVEMENTS WITH THE HAMILTON WATCH CO. U.S.A. UNDER THE CENTER SECONDS WHEEL, AND THE ENGRAVING ADJ TEMP. AND 6 POS. UNDER THE CENTER SECONDS BRIDGE. THE ADJ. TEMP. AND 6 POSITIONS IS ENGRAVED UNDER THE CROWN WHEEL WITH BU. AERO. U.S. NAVY ENGRAVED OVER THE CENTER SECONDS WHEEL IN BLOCK FONT. THE 4992B (NUMBERS DECREASE IN SIZE TO THE B), AND THE 22 JEWELS PERPENDICULAR TO THE CIRCUMFERENCE ON THE FOURTH WHEEL BRIDGE. ARE THE EARLIEST EXAMPLES NUMBERED. 4C001 THROUGH APPROXIMATELY 4C1000 WITH U.S. ARMY AIR CORPS AS WELL AS BU. AERO. U.S. NAVY ALSO SEEN ENGRAVED ON THE FOURTH WHEEL BRIDGE UNDER THE 4992B 22 JEWELS PARALLEL WITH THE CIRCUMFERENCE, FACING INBOARD NOTE; BU. AERO. U.S. NAVY IS NOT SEEN AFTER ABOUT 4C1250

THE NEXT CHANGE TO THE ENGRAVING ON THE PLATES MOVED THE HAMILTON WATCH CO. U.S.A. ABOVE CENTER SECONDS WHEEL, ELIMINATED THE ENGRAVING ADJ TEMP. AND 6 POS. UNDER THE CENTER SECONDS BRIDGE. THE ADJ. TEMP. AND 6 POSITIONS IS ENGRAVED UNDER THE CROWN WHEEL.IN BLOCK FONT. U.S. ARMY AIR CORPS ALL BLOCK FONTS IS NOW ENGRAVED ON THE FOURTH WHEEL BRIDGE UNDER THE 4992B 22 JEWELS PARALLEL WITH THE CIRCUMFERENCE, FACING INBOARD ENGRAVING OF THE FONT ON THE ADJ TEMP. AND 6 POS.CHANGES TO BOLD ITALIC ABOUT 4C3000 U.S. ARMY AIR CORPS REMAIN BLOCK FONT

ON OR ABOUT 4C3100 U.S. GOVT ALL BLOCK FONT.STARTS TO SHOW UP ON THE FOURTH WHEEL BRIDGE UNDER THE 4992B 22 JEWELS PARALLEL WITH THE CIRCUMFERENCE, AS WELL BUT WITH THE PLACEMENT MOVED FROM THE OUTBOARD POSITION TO THE INBOARD POSITION FACING OUTBOARD THE LAST U.S. ARMY AIR CORPS SEEN OCCURS AROUND 4C3500 RANGE

ON OR ABOUT 4C5000 THE 4922B 22 JEWELS ROTATE 90 DEGREES ON THE FOURTH WHEEL BRIDGE PLATE ADJ. TEMP. AND 6 POSITIONS IS BOLD ITALIC HOWEVER U.S. GOVT REMAINS ALL BLOCK FONTS. U.S. GOVT STARTS TO DISAPPEAR ON OR ABOUT THE 4C40000 RANGE AND SHOW UP SPORADICALLY INTO THE4C98000 RANGE AND PERHAPS FURTHER

FINAL ENGRAVING LAYOUT OF THE 4992B

PLEASE ADD YOUR OBSERVATIONS
MAHALO SCOTT

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Just got a late model 4992B today.

AN 5740-1
STOCK NO. 6645-557-0321
MFR'S. PART NO. 33106
CONTRACT NUMBER
DA-36-038-ORD-20573
SERIAL NO. AF-58-8557
HAMILTON WATCH
COMPANY

DIAL 24 HOUR G.C.T. BLACK
White hour, minute and second hand
Inside back STAR WATCH CASE CO.
BASE METAL
R827898

Movement Serial # 4C122574
HAMILTON WATCH CO.
U.S.A.
NO U.S. GOVT markings on movement
4992B
22 JEWELS
ADJ. TEMP.
AND 6
POSITIONS

It appears the late model 4992B movements changed from wide damaskeened to narrow. The movement serial number does not have black in the stamping. The back cover is marked COMPANY vs CO. These observations are consistant with Wayne Hanley's post above on August 27, 2009.

Also, the example I picked up has a slightly different regulator scale than posted pictures so far.

RR

Here's mine. It belonged to a friend who'd been a USAF bombardier/navigator. I expect when he was issued this he was with the 92nd BG flying B-52s.

Movement:

Case, back outside:

AN-5740-1
STOCK NO. 6645-557-0321
MFR’S. PART NO. 33106
CONTRACT NUMBER
DA-36-038-ORD-20573
SERIAL NO.AF-58-7665
HAMILTON WATCH
COMPANY

Case, back inside:

STAR WATCH CASE COMPANY
*
BASE METAL
R828161

From previous...

Movement: 4C122235

very good article

Here's mine 4992B in silver keystone case K045684. Movement no. 4C71655. On case back:AN 5740, mfr's part no. 33106 serial number 12009 Hamilton Watch Co R88-W-510

Hi Scott
What do you think of this one BU AREO.U.S.Navy?
2211170xxx55
Hub.

Hubert,

That number you posted turned out to be an eBay auction number, we are not supposed to discuss such things in public view. Notice the admonition at the top of this forum: "Please discuss "ON-LINE TRADING" in that titled forum." This time, to avoid any liability issues that could possibly develop, I disguised your auction number.

Then I checked over the closed auction and found movement number 4C1638 marked BU. AERO. U.S. NAVY, Case number 1300867, no markings on case-back but correct black 24-hour GCT dial and white hands. Many scratches on movement, case worn, bow stretched, crown worn smooth to brass. All that being said, although the Navy marking usually commands a premium this one looks to be in rather well-worn condition and the seller only mentions "minor use scratches" in their description. Still sold for 565.00 plus 15.00 for shipping.

Don

This one I do not have in hand as yet. Roger Nolfe is putting a staff in it for me.

NAVIGATION MASTER WATCH
TYPE AN-5740
H.W.Co. PART NO 33106
DAAA25-68 - 0066
U.S.

#4C143714

I am taking this info off the pics, which are not very clear.

Having the watch in hand I made 2 corrections to the info I posted. Was this watch made in 1968?

Roger Nolfe did a great job getting this watch up and running for me. It is running great and keeps great time. Thanks Roger for bailing me out once more!

Hi Guys,
New guy here, Have a 4992-B # 4C-2064.
And a 3992-B # 3C-2480. Both have typical markings for the serial number range. Both are in 800 Silver cases and the cases have matching case numbers. Hope this helps out in your research.
Joe M.

Hi Dr. Debbie Irvine,
Your very welcome, I have three other Military watch's left from a large collection I had many years ago, some may have seen them on display at the ***** museum, they were there for a few years.

If any one is doing a study or research on the Hamilton 23, the Hamilton 987-S Military Wrist Watch, or the Waltham 1622-AN-5740, I would be more than happy to get the serial numbers off them for who ever is doing the study.
Regards
Joe M.

Hi Again,
Back on 7-11-13 and 7-12-13 I made my first two post about the 4992-B and a 3992-B that I had in my collection.I gave the serial numbers of both to help with the research that is going on. I also said that if anyone was doing research on some other Military Watches that I had I would be willing to help. []
Regards
Joe M.

Hi Again,
I'm not much of a computer or camera guy but am going to give it a try. The first three Photos should be of the 4992-B and the second three should be of the 3992-B. Hope I got it right.
Joe M.

My contribution 4992B with British 3992B military dial and cool red sweep hand.

Case Back:
AN 5740
Stock No.
Mfr's Part No.-33106
Contract Number
DA-36-038-ORD-9888
Serial No. AF-52-8713
Hamilton Watch Co.

Movement # 4C79914 Year:1942
Keystone Base Metal K359964


Civilian conversion or an early supply to our British Allies?