On December 18, 1960, Seiko put on sale a watch whose entire reason for existing was a standard: the first Grand Seiko, known by its caliber as the 3180, built to meet a chronometer specification Seiko administered itself because the Swiss bureaus were an ocean away. A 25-jewel hand-wound movement adjusted to minus 3 to plus 12 seconds a day, in a 35 mm case, most of them gold-capped, with platinum examples above and genuinely scarce steel below. Around 36,000 were made. The end of the run is the file's first recorded dispute: caseback serials peter out in August 1963, while most published guides say 1964.
Collectors sort the run by its logo eras, from carved to printed to raised, and by the lion medallion on the caseback that predates the GS medallion of later families. It is the plainest-looking watch in this file and the one carrying the most history per millimetre: everything else here descends from the standard this watch was built to prove.
The founding document, priced like one when honest and like a parts watch when not. Gold-cap wear is the condition question, the dial the originality one, and steel examples deserve deep skepticism, because scarcity attracts fabrication.
Production windows and specifications compiled from documented collector references and period catalogs, cross-checked across independent sources; manufacturer records for this era are approximate by Seiko's own account.