Vintage Watch | Grand Seiko 5646 Cushion Case

Grand Seiko 5645-7000: November 1970 Cushion Case, Date Only (Fully Serviced)

A vintage Grand Seiko 5645-7000 is a 56GS automatic: cushion steel case, white dial, date at 3, Caliber 5645. This one is November 1970. The dial is white, with grey smoke-like patina near 7 and 8 o’clock and a little age at the dial edge. The gold medallion on the caseback is damaged.

What Grand Seiko 56GS is

56GS is the first automatic Grand Seiko, introduced in 1970 as the last mechanical GS series before quartz took the market. It is thinner than the 61GS that came before it. Three calendar versions share the family: 5641 with no date, 5645 with date only, 5646 with day and date. All are 25 jewels and 28,800 beats per hour. The dial is marked HI-BEAT. That is Seiko’s own wording. It is 8 beats a second, not the 36,000 of the 45-series or 61GS. Suwa built the movement. It hacks, it hand-winds, and the date quick-sets. The same 56 architecture, in a less finished form, also sat in Lord Matic and automatic King Seiko. In a Grand Seiko the finishing and the regulation are the point.

What is the 5645-7000's 7000 refers to?

Reference 7000 is the C-line cushion of the 56GS, about 36 mm across, 42 mm lug-to-lug, 18 mm lugs, roughly 10–11 mm thick. Brush on the top, polished flanks, a shape that sits lower and wider than the sharp 44GS. On this watch the case still reads as that 1970s cushion. It is not a later polish that has rounded the form away.

The Grand Seiko 5645 Condition, stated as it is

The dial is white and still original. Near 7 and 8 o’clock there is a grey smoke patina developed, and the edge of the dial shows a little age. That is not a clean white 5645. It is an honest one. The gold GS medallion on the caseback has a small chip ageing. Time, date and the movement are the working parts; the medallion is the cosmetic one. Crystal and case carry ordinary use for a 1970 watch.

Specification

Maker: Grand Seiko / Seiko

Model: 5645-7000

Era: November 1970
Case: Stainless cushion, about 36 mm, 42 mm lug-to-lug, 18 mm lugs. Case in good condition.

Dial: White, grey smoke patina near 7–8, slight edge age; HI-BEAT, GS mark, date at 3

Caseback: Gold medallion with a smalll chip ageing 

Movement: Automatic Caliber 5645, 25 jewels, 28,800 bph, fully serviced by our watch maker in Japan. Hacking, hand-wind, date quick-set working perfectly. 

A November 1970 Grand Seiko 5645-7000 is the date-only 56GS in the cushion case. Buy it for the movement and the form. Price the smoke on the dial and the medallion as they are.

Shown on a leather strap. Any colour from our Grand Italian or Kyoto Series on request.