SECONDE MARCHEWATCHMAKING WITH COMPLETE TRANSPARENCY

CALIBRE HISTORY

Seiko
6309A

The Seiko 6309A is a Japanese 63 series automatic mechanical caliber, launched in 1976. The Seiko Technical Guide documents movement at 21,600 vibrations/hour with a quick-correction bilingual day-date calendar. Specialized registers give it for 17 rubies, with central seconds and without manual winding by the crown.

2 documentsEN
Mechanical study drawing of the Seiko 6309A calibre, vintage workshop notebook style
MECHANICAL STUDY · WORKSHOP NOTEBOOK

MOVEMENT RESOURCES

Everything in one place.

All documents currently available for this movement are gathered here. When a SECONDE MARCHE workshop plan exists, it is presented first.

Available documentsNo payment · no account
TECHNICAL DOCUMENT · PDFOpen access

Technical guide

A high-definition workshop document structured for direct use at the bench, so the useful information is quick to find.

  • PDF HD · EN
  • Direct download
  • No payment · no account
TECHNICAL DOCUMENT · PDFOpen access

Parts catalogue

A high-definition workshop document structured for direct use at the bench, so the useful information is quick to find.

  • PDF HD · EN
  • Direct download
  • No payment · no account

SPECIFICATIONS

PeriodFrom 1976; production of the 6309 family until the end of the 1980s according to specialized registers
ManufacturerSeiko
WindingAutomatic, without manual winding by the crown
Frequency21,600 vibrations/hour (3 Hz)
Jewels17 jewels
Power reserveAbout 47 hours according to Ranfft and Caliber Corner
Diameter27.0 mm of casing (about 27.4 mm overall according to Ranfft)
Height5.2 mm according to the Seiko Technical Guide
ComplicationsDay, Quick Correction Bilingual Date, Central Seconds

TIMELINE

Movement
timeline.

  1. Seiko 6309A Documented Launch

  2. End of the production period commonly attributed to the 6309 family

FAMILY

Related calibres

6308A6319A6349A61XX

Sources

Public sources used for this profile.

Last checked : 9/8/2026