Seiko 9S55

	Brand:	Grand Seiko, Seiko, Shizukuishi Watch Studio
	Family:	Seiko 9S5x Family
	Height:
	Jewels:	26
	Reserve:	hours
	Frequency:	28,800 A/h
	Winding:	Automatic, Bi-Directional Automatic Winding
	Diameter:
© Seiko	Complications:	Date, Hacking Seconds, Hand Winding, Quick Date Correction
	Hands:	Central Hour Hand, Central Minute Hand, Central Seconds Hand, Date Window at 3:00

Distinguishing Technical Characteristics
Clockwise Balance Cock Balance Balance at 1:30
Production: 1998 – 2010
1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s

Cal. 9S55 is an automatic movement with date produced by Shizukuishi Watch Studio for Grand Seiko. Launched in 1998, it was the first modern Grand Seiko mechanical movement and the basis for the Grand Seiko 9S5x movement family. It is a modern movement operating at 8 Hz (28,800 A/h) and is accurate ti -3/+5 seconds per day. Cal. 9S55 was phased out in favor of Cal. 9S65 in 2010.

Cal. 9S55 was based on the design of Cal. 4S35, the first modern high-end mechanical movement from Seiko. That movement, in turn, was developed from the design of the 1970 Cal. 5206, which had been retired in the 1970s and revived in 1992.