Hamilton H-50

Probable

The Khaki Field Mechanical caliber. Published jewel counts disagree: Hamilton and several retailers state 17, matching the 2801-2 base, while other published specifications for the same watch state 25. The catalog records the disagreement rather than choosing, because a jewel count is exactly the kind of detail an examiner would otherwise treat as decisive.

Specifications

Movement manufacturer: Hamilton
Base caliber: ETA 2801-2
Frequency: 21,600 vph (3 Hz)
Power reserve: 80 hours
Winding: manual
Complications: Centre seconds

Architecture

A hand-wound ETA 2801-2 with the balance slowed and the barrel revised for an extended reserve. Centre seconds, no date.

Authentication notes

MovementHigh confidence
No rotor — the winding behaviour is the test
The H-50 is hand-wound. A watch presented as a Khaki Field Mechanical that runs after being shaken, or that shows a rotor through any aperture, does not contain this caliber. This is the cheapest and most reliable check available on the reference.

Service practice

A 2801-2 at heart and serviceable as one, with the same caveat as the H-10: escapement parts from a standard 2801-2 restore the movement to running order but not to the 80-hour specification.

Open questions

OpenConflicting researchMedium

Jewel count of the Hamilton H-50

Does the H-50 carry 17 jewels, as Hamilton's own specification and its ETA 2801-2 base imply, or 25 as other published specifications for the same reference state?

Conflicting claims

Hamilton's own product specification and several retailers state 17 jewels; other published specifications for reference H69439931 state 25. Both appear in current circulation.

Scope Small in itself and disproportionately consequential in use, because a jewel count is visible on the movement and an examiner will reasonably treat it as decisive. Until it is settled against a Hamilton technical document the catalog asserts no figure, and no finding should rest on one.

Related calibers

Built on
ETA 2801-2

References using this caliber

Hamilton H69439931Factory
Khaki Field · Whole production

Provenance of this record

Sources & Evidence

Primary sourceManufacturer documentation

Hamilton — current collection and caliber specifications

Hamilton International Ltd (Swatch Group)

Accessed: 2026-08-19

Cited for

This referenceHigh confidence

View source ↗

Secondary sourceCollector research

Hamilton collector research on the electric calibers, named models and case reproduction

Collector communities and specialist dealers

Accessed: 2026-08-19