Suwa Seikosha produced the 5600 series of high-end automatic watch movements for Seiko in the 1960's and 1970's.
This line was used in various Lord Matic, King Seiko, and Grand Seiko models from 1968 through 1976. It appeared first in the 1968 Lord Marvel, next in 1969 in the King Seiko 56KS, and finally in 1970 in the Grand Seiko 56GS. It was also used in two other Seiko models - the Seiko Duotime and Seiko Chronometer.
Unlike previous Grand Seiko movements, production of Calibre 5600 was highly automated. This made the movements cheaper and helps to this day since parts are more plentiful. But the speed of the movement was reduced from “Hi-Beat” 36,000 A/h of its predecessors.
The 5600 family was introduced in 1968 for the Lord Matic and first appeared in King Seiko guise the following year. This was the first Suwa movement used in the Daini King Seiko line.
The 5600 family was produced in four grades and with three complication sets
Speed | Movement | Date | Jewels | Power Reserve | Complications | Notes |
---|---|---|---|---|---|---|
21600 | 5601A | 1968-1978 | 23 | 47 hours | Lord Matic | |
5605A | 1968-1971 | 25 | 47 | Date | Lord Matic | |
5606A | 1968-1978 | 23/25 | 47 | Day, date | Lord Matic | |
5619A | 1972-1974 | 25 | 47 | Date, dual time 12h | Lord Matic, Duotime | |
28800 | 5621A, 5621B | 1969-1973 | 25 | 47 | King Seiko | |
5625A, 5625B | 1968-1974 | 25 | 47 | Date | King Seiko, Chronometer | |
5626A, 5626B | 1968-1973 | 25 | 47 | Day, date | King Seiko, Chronometer | |
5641A | 1971-1973 | 25 | 47 | Grand Seiko | ||
5645A | 1970-1974 | 25 | 47 | Date | Grand Seiko | |
5646A | 1970-1975 | 25 | 47 | Day, date | Grand Seiko |