Within the world of vintage Seiko, Grand Seiko – distinguished by the “GS” on dial/crown and gold medallion on its caseback, as seen on this crisp full-serviced 1970 Grand Seiko 5646-7000 automatic dress watch here – inhabits the top of the food chain, simple as that. Grand Seiko demonstrates well what's so incredible about Japanese craftsmanship, namely, supreme attention to detail and refinement.
Grand Seiko – with 51 different models – were simply the most painstakingly designed and exquisite watches made by Seiko, produced by both the Dani and Suwa factories, including the 56GS line here.
The 56GS series, often referred to as “Ultra Thin,” included 18 variations - and transitioned from manual wind to automatic beginning in the 1970s. That said, precision level suffered as a result, but reliability level increased with its balance of maintenance, reliability, and precision.
The Grand Seiko 56GS series is the final Grand Seiko model Seiko made before production ceased in 1976, a self-inflicted fatality of the Quartz Crisis (which was brought on by the Seiko invention of the quartz watch in 1969).
Produced from mid/late 1970 through circa early 1976, the GS 5645/6 (with the 5646 being the day/date variant) is regarded as one of the best combinations of reliability, precision, and maintenance within the original GS lineup.
Of note, its relatively uncomplicated to get parts for the 56GS, despite over half a century of time passing since its production - a slightly less fine-tuned calibre 56 movement was also used in King Seiko and Lord Matics.
But make no mistake, Grand Seiko marked - and still continues to mark - the very best Seiko has to offer, easily on par with the vast majority of what Switzerland has to offer by way of competition.
This Grand Seiko comes on a leather strap, and with nylon strap, rugged travel case, and springbar tool.
Hi-Beat 1970 Grand Seiko 5646-7000 Automatic Dress Watch
DIAL: Brilliant silver starburst Grand Seiko-signed dial, with applied hour indices; no blemishes or dial edge patina present. Matching slender baton hour, minute, and second hands - both day and date functions work as designed.
CASE: Grammar of Design stainless-steel case measures 36.5mm (37mm w/crown) x 41.5mm; gold Grand Seiko medallion on caseback is in overall good condition, with limited wear - these are frequently quite worn to the point of absence from the wearer's sweat over the decades.
CRYSTAL: Seiko crystal, no scratches, edge chips, or blemishes present.
BAND: This Grand Seiko comes on a brown leather strap; it also comes with a red and yellow nylon strap.
MOVEMENT: Grand Seiko hi-beat 5645A automatic movement; the 25-jewel movement beats at 28,800 bph and was produced by Seiko's Suwa factory in April 1970. We have performed a full service on this Grand Seiko.
CROWN: Correct “GS”-signed Grand Seiko crown.
Find an original vintage 1970s Seiko advert featuring Grand Seiko watches, here.