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The Encyclopedia of Horology

Movement record · Japan

Seiko Calibre 6139

Partially verified

One of the earliest automatic chronograph calibres to reach the market, notable for its vertical clutch chronograph coupling and single push-button-free crown-based control layout in some references.

Technical specifications

Diameter
Approx. 27 mm
Height
Approx. 6.5 mm
Jewels
17 or 21 depending on market version
Frequency
21,600 vph (3 Hz)
Power reserve
Approx. 40 hours
Winding
Self-winding with Seiko's Magic Lever winding system
Setting
Pull-out crown
Escapement
Swiss-type lever, Seiko manufacture
Balance
Diashock-protected balance
Complications
Column-wheel automatic chronograph, Day-date

Identification features

  • Column-wheel chronograph mechanism
  • Day and date apertures typical of the family

Known variants

  • 6139 family variants across export markets

Servicing notes

Parts and service expertise are available through specialist vintage Seiko chronograph servicers.

General guidance only. Antique movements should be serviced by a qualified watchmaker.

Historical significance

Central to the historical debate over which manufacturer first brought an automatic chronograph to market in 1969.

Related photographs

Black Seiko watch close-up
Black Seiko watch close-up — gcardinal from Norway, CC BY 2.0. Wikimedia Commons file page
Dial detail of a Seiko Speed-Timer Chronograph Automatic 6138-0040 ("Bullhead"), 1976
Dial detail of a Seiko Speed-Timer Chronograph Automatic 6138-0040 ("Bullhead"), 1976 — Dnalor 01, CC BY-SA 3.0. Wikimedia Commons file page
Seiko SKX781 Orange Monster diver watch (2026-02-13)
Seiko SKX781 Orange Monster diver watch (2026-02-13) — Olgierd Rudak, CC BY-SA 4.0. Wikimedia Commons file page

No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.

Sources & references

  1. Seiko historical literature
  2. Collector research into 1969 automatic-chronograph priority, which remains debated

Where sources disagree, the disagreement is stated rather than resolved silently.