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The Encyclopedia of Horology

Clock · Alarm clock

Diamond (Zuanshi) brand mechanical alarm clock

Partially verified

This mechanical alarm clock was manufactured in Shanghai, China, by the Shanghai Stopwatch Factory between 1970 and 1975. The object features a metallic casing and a blue dial marked with the Diamond (Zuanshi) brand. It was produced for the export market, as evidenced by the English-language markings on the dial. The clock measures approximately 97 mm in height, 140 mm in width, and 85 mm in depth. The design includes a clear graphical diamond logo on the dial above the central hand arbor. The rear of the clock features control knobs and a regulation scale for the movement.

Front view of the Diamond (Zuanshi) brand mechanical alarm clock, showing the blue dial, gold-toned hands, and the faceted diamond logo.
Front view of the Diamond (Zuanshi) brand mechanical alarm clock, showing the blue dial, gold-toned hands, and the faceted diamond logo. — Science Museum Group. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
collection.sciencemuseumgroup.org.uk
Category
Clock · Alarm clock
Maker / attribution
Shanghai Stopwatch Factory
Reference
Not recorded
Catalogue / lot identifier
2021-625
Source-reported date
1970-1975
Source-reported place
China

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

Design and Dial

The alarm clock presents a rectangular profile with a metallic outer frame and a blue dial. The dial layout includes prominent white indices and the Diamond (Zuanshi) brand symbol, depicted as a faceted diamond motif located above the center of the dial.

The hands are gold-toned and include a distinct alarm-setting hand. The dial is also printed with the text 'MADE IN CHINA', consistent with its history as an export model produced during the 1970s for consumers in Britain.

Evidence for this section
  • “blue dial and metallic casing.”
  • “under the Diamond (Zuanshi) brand name and exported to Britain.”

Manufacturing History

The clock was produced by the Shanghai Stopwatch Factory, an entity that emerged from a series of institutional changes within the Shanghai clock industry. Initially formed as the Tak On Clock Factory in 1932, the firm underwent significant changes following destruction in 1937 and subsequent rebuilding.

By 1955, the factory was consolidated into the Shanghai Clock and Watch Industry Company. Following a shift toward specialized production in 1959, the factory adopted the name Shanghai Stopwatch Factory in 1966, under which it continued to produce alarm clocks such as this specimen.

Evidence for this section
  • “This company was the successor to the original Tak On Clock Factory”
  • “In 1955 the company was amalgamated with other factories and became known as the Shanghai Clock and Watch Industry Company”
  • “it took on the Shanghai Stopwatch Factory name in 1966, but continued to make alarm clocks such as this one for export”

Movement and Rear Configuration

The rear of the clock housing contains the manual winding and setting components. It features a regulation mechanism marked with a scale including plus and minus indicators to facilitate adjustment of the mechanical movement's timekeeping rate.

The mechanical movement is encased entirely within the metallic body of the clock.

Evidence for this section
  • “Alarm clock with mechanical movement”

Open research questions

  • What specific internal caliber is used in this 1970s Shanghai-produced mechanical alarm clock?
  • What were the specific distribution channels utilized for the export of Diamond brand clocks to Britain in the 1970s?

Source evidence

Recorded claims and source quotations for Diamond (Zuanshi) brand mechanical alarm clock
FieldSource-reported valueSource quotation
MakerShanghai Stopwatch Factory“Made by the Shanghai Stopwatch Factory”
BrandDiamond (Zuanshi)“under the Diamond (Zuanshi) brand”
Date1970-1975“1970-1975”
Measurements97 mm x 140 mm x 85 mm“overall: 97 mm x 140 mm x 85 mm,”
Accession number2021-625“2021-625”
Place of manufactureShanghai, China“Shanghai, China, 1970-1975.”

Visible details

  • Blue dial with central diamond logo and English text
  • Metallic rectangular casing with four small feet
  • Rear regulation scale marked with plus and minus symbols
  • Three gold-toned hands with a separate alarm indicator hand

Research qualifications

  • The specific export destination within Britain is not documented beyond general statements
  • The precise internal mechanical escapement configuration is not visible

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

Consulted source

Alarm clock with mechanical movement

Reviewed 2026-10-26 · Record b257c4e6c3

Terms in this record

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

Other alarm clock records