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The Encyclopedia of Horology

Pocket watch · Open-face military pocket watch

Hamilton Base Metal Open Face 'Navigation Master' Military Pocket Watch

Partially verified

According to the auction catalog, this open-face military pocket watch by Hamilton Watch Co. dates to circa 1941 and has a 50.00 mm base metal case. The black dial features white Arabic numerals, an inner chapter ring calibrated to 24 hours, white spade hands, a center sweep seconds hand, and is signed 'G.C.T.' The source reports a stem-wound and set 22-jewel, 3/4 plate nickel movement adjusted to temperature and six positions, numbered 4C3393 and signed for the U.S. Army Air Corps. The case back is engraved with military specification designations including AN 5740 and manufacturer part number 4992B.

Front view of Hamilton open-face military pocket watch showing black 24-hour dial and white hands
Front view of Hamilton open-face military pocket watch showing black 24-hour dial and white hands — Hindman. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.bidsquare.com
Category
Pocket watch · Open-face military pocket watch
Maker / attribution
Hamilton Watch Co.
Reference
AN 5740 / 4992B
Catalogue / lot identifier
84
Source-reported date
Circa 1941
Country
United States
Source-reported serial
AF-42-7804

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Dial and Navigation Configuration

The watch features a black dial signed 'G.C.T.' The layout includes Arabic numerals at five-minute intervals and an inner chapter ring calibrated to 24 hours.

The timepiece uses white spade hands and a center sweep seconds hand. The crystal is set within a fluted, coin-edged bezel, with a pendant and bow located at the 12 o'clock position.

Evidence for this section
  • “black dial signed G.C.T.”
  • “Arabic numerals with inner chapter ring calibrated to 24 hours”
  • “white spade hands with center sweep seconds hand”

Case and Military Markings

The watch is housed in a 50.00 mm base metal case. The inner case back is marked 'KEYSTONE BASE METAL 006416.'

The case back is engraved with military identification including 'PART NO. AN 5740', 'MFR'S PART NO. 4992B', 'SERIAL NO.AF-42-7804', 'CONTRACT NO. W535o.c-28072', and 'HAMILTON WATCH CO.'

Evidence for this section
  • “50.00 mm case diameter”
  • “Inner case back: KEYSTONE BASE METAL 006416.”
  • “Case back engraved: PART NO. AN 5740 MFR'S PART NO. 4992B SERIAL NO.AF-42-7804 CONTRACT NO. W535o.c-28072 HAMILTON WATCH CO.”

Movement Technical Description

The watch contains a stem-wound and set 22-jewel 3/4 plate nickel movement, adjusted to temperature and six positions. It is signed for 'HAMILTON WATCH CO U.S.A' and 'U.S.ARMY AIR CORPS.'

The reported movement number is 4C3393. The internal state of the movement is not visible in the provided imagery.

Evidence for this section
  • “stem wound and set 22 jewel 3/4 plate nickel movement adjusted to temperature and six positions signed HAMILTON WATCH CO U.S.A U.S.ARMY AIR CORPS.”
  • “Movement number: 4C3393.”

Open research questions

  • Verification of the serial number AF-42-7804 against U.S. Army Air Corps inventory logs.
  • Documentation of the manufacturing period for Hamilton movements with serial prefix 4C.

Source evidence

Recorded claims and source quotations for Hamilton Base Metal Open Face 'Navigation Master' Military Pocket Watch
FieldSource-reported valueSource quotation
Case diameter50.00 mm“50.00 mm case diameter”
Dial inscriptionG.C.T.“black dial signed G.C.T.”
Movement description22 jewel 3/4 plate nickel movement“stem wound and set 22 jewel 3/4 plate nickel movement adjusted to temperature and six positions”
Movement number4C3393“Movement number: 4C3393.”
Inner case back markKEYSTONE BASE METAL 006416“Inner case back: KEYSTONE BASE METAL 006416.”
Case back engravingPART NO. AN 5740 MFR'S PART NO. 4992B SERIAL NO.AF-42-7804 CONTRACT NO. W535o.c-28072 HAMILTON WATCH CO.“Case back engraved: PART NO. AN 5740 MFR'S PART NO. 4992B SERIAL NO.AF-42-7804 CONTRACT NO. W535o.c-28072 HAMILTON WATCH CO.”
Estimated DateCirca 1941“Circa 1941”

Visible details

  • Black dial featuring central 'G.C.T.' signature
  • Inner 24-hour chapter ring and outer minute divisions with Arabic numerals at five-minute intervals
  • White spade hands paired with a thin central sweep seconds hand
  • Fluted, coin-edged bezel and threaded case rim
  • Pendant with bow at the 12 o'clock position (above 24 on the dial)

Research qualifications

  • Movement condition and back engravings are catalogued by the source but not visible in the provided photograph

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Hamilton, Base Metal Open Face 'Navigation Master' Military Pocket Watch, Circa 1941 sold at auction on 4th October | Bidsquare

Reviewed 2026-10-22 · Record fb573c2759

Terms in this record

Glossary explanations for terms named in this object’s record.

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