Seiko 6100

The "Seikomatic 5" 6100 series was a family of mechanical watch movements from Seiko in the 1960's and 1970's.

Produced from 1967 through 1974, the 6100 family was used in many high-end Seiko watches. It was available in both regular 21,600 A/h and high-beat 36,000 versions and both manual winding and automatic versions.

The Hi-Beat 61GS models, introduced in 1968, upstaged the slower 62GS models. That movement was retired in 1969, with the 6100 becoming the high-end Grand Seiko movement. But producing these movements was highly labor-intensive, so Seiko began mechanizing the next year. The 5600 calibre family quickly proved itself for reliability and quartz movements boasted better accuracy, leading to the demise of the 6100 by 1974.

Seiko "resurrected" the 6159A movement in 1975, creating the 6159B for their 600M diver. There is little parts interchange between this later movement and earlier members of the family. It features larger pins to attach the heavier hands of the diver, along with different balance cock and regulating pins similar to the Seiko 4S24.

Winding	Speed	Model	Year	Notes
Manual	21600	61A	1968
		6102A		Date
		6110A	1971	Railroad Watch
Automatic		6105A	1968	Quickset date
		6105B		Quickset date, hacking
		6106A, 6106B, 6106C	1967	Day, date, hacking
		6109A		Day, date, small rotor
		6117A	1968	Quickset date, GMT 24 hour
		6117B		Quickset date, GMT 24 hour, hacking
		6118A		Quickset date
		6119A, 6119B, 6119C	1970	Day, date
		6138A, 6138B	1970	Chronograph, hour counter, quickset day and date
		6139A, 6139B	1968	Chronograph, hour counter, quickset day and date
	36000	6145A	1968	Date, Grand Seiko
		6146A	1968	Day, date, Grand Seiko
		6155A	1971	Date, Grand Seiko Special
		6156A	1970	Day, date, Grand Seiko Special
		6159A	1967	Quickset date, Diver 300
		6159B	1975	Quickset date, hacking, Diver 600
		6185A	1969	Grand Seiko Veri Fine Adjusted
		6185B		Grand Seiko Veri Fine Adjusted, hacking
		6186A	1972	Day, date, Unruhstop, Grand Seiko Veri Fine Adjusted

See Also

• Seiko 6139

External Links

• The History of Grand Seiko Hi-Beat Movements: Seiko’s Affinity to Hi-Beat Movement – Part One

Description: Manual winding or automatic Functions: Hours, minutes, central seconds Optional day and date window Optional quickset Optional hacking Data: Diameter: 12 ligne (27.0 mm), H: 5.25 mm 17 jewels 21,600 A/h Power reserve: 46 Hours Production period: 1967-1974