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You are here: Home / Movements / Seiko 8L21

Seiko 8L21

Last Update: February 2, 2020

Brand:Seiko, Shizukuishi Watch Studio
Family:
Seiko 9S5x Family
Height:
Jewels:24
Reserve: hours
Frequency:28,800 A/h
Winding:Automatic, Bi-Directional Automatic Winding, Seiko Magic Lever Winding
Diameter:
  Complications:Hand Winding
Hands:Central Hour Hand, Central Minute Hand, Central Seconds Hand
Distinguishing Technical Characteristics
Clockwise Balance Cock
Screw Regulator
Balance
Balance at 1:30
Production: 2003 – 2007
1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s

Cal. 8L21 was an automatic watch movement produced by Seiko’s Shizukuichi Watch Studio for the Brightz brand from 2003 through 2007. It was based on the Grand Seiko Cal. 9S51 which was produced at the same time. The Prospex/Brightz Cal. 8L35 was similar but added a date complication.

Cal. 8L21 was used in the Brightz SAGL model line. This appeared in Seiko catalogs and the Seiko Japan website from 2003 through 2007.

ProductionApplicationWindingJewelsNotes
8L212003-2007Brightz SAGLAutomatic24Similar to 9S51
8L342000Railway pocket watchManual20Small seconds
8L352000-presentBrightz SAGQ
Prospex SBDX
Prospex SLA
Automatic26Date, similar to 9S55
8L362011-presentCredor GCBZ
Galante SBLM
Automatic27GMT, similar to 9S56
8L382010-2015Galante SBLLAutomatic26Open Heart
8L75-2005Credor GCBRAutomatic26Date, similar to 9S55
9S511998-2009GS SBGRAutomatic24No date
9S542001-2010GS SBGWManual20No date
9S551998-2010GS SBGRAutomatic26Date
9S562002-2010GS SBGMAutomatic27GMT, no date

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