Knowledge Center

Professional Authentication Platform

Hamilton 992B

Probable

Over half a million produced, making it the second most numerous American railroad-standard movement. Sold as a movement rather than as a watch: the case was a separate purchase, so case and movement by different makers is the normal condition.

Specifications

Movement manufacturer
Hamilton
Production
1940–1969
Jewels
21
Winding
manual
Markings
Grade designation and serial number on the movement; serial numbers carry a C prefix.

Architecture

16-size, 21-jewel, lever-set railroad-grade movement with a motor barrel and an Elinvar Extra hairspring. Adjusted to temperature, isochronism and positions.

Authentication notes

  • MovementProbable

    Serial prefix and jewel count must agree with the grade marking

    Three independent things state the grade — the engraved designation, the serial prefix, and the physical jewel count — and a genuine movement has all three agreeing. The engraving is the one that can be altered. Where they disagree, the jewel count is the evidence and the engraving is the claim.

Related calibers

  • Related caliber

    Hamilton 950B

    Same size and era, different grade. The price gap between them is what motivates the alteration.

References using this caliber

Provenance of this record

Sources & Evidence

Secondary sourceCollector research

NAWCC message board and encyclopedia material on Hamilton Watch Company production

National Association of Watch and Clock Collectors

Accessed
2026-08-19

Cited for

This referenceProbable
View source
Secondary sourceCollector research

Pocket Watch Database — American watch serial number lookup

Pocket Watch Database

Accessed
2026-08-19

Cited for

This referenceProbable
View source

Last verified: Not yet reviewed