Grand Seiko “Hammered Steel” 5646-7040

Model: Grand Seiko “Hammered Steel” 5646-7040

Year: June 1973

Features:

The Collection. Pick any 56GS calibre and you’ll have an excellent vintage watch on your wrist - but the 5646-7040 on offer today has a few standout elements that set it apart from the pack.

The Production. To start with, it was only produced for a single month. I know, that’s a bizarre claim to make - but it’s supposedly true. Even anecdotally, whenever I spot a Hammered Steel in the wild, the serial number always starts with a 36 - meaning June 1973. Seiko produced the dozens of other 56GS pieces over years, not even just months. And while it was Grand Seiko’s final collection before closing its mechanical doors in 1975 due to the Quartz “Crisis”, it didn’t stop producing other 56GS models until the very end. 

The Dial. This is the only vintage Grand Seiko to feature Arabic numerals. To clarify - not just the only 56GS, but the only vintage Grand Seiko, full stop. 134 watches, but only one with numbered hour markers. 

The Calendar Wheel. Why are Saturdays blue and Sundays red, as shown above, on Seiko day wheels? Red symbolises a day of closure, whereas blue was chosen (from the limited CMYK palette available to printing presses at the time) to represent a half-day of work. You’ll often see the existence of the coloured days being linked to the 1973 Oil Crisis, but that’s a myth. The existence of the 6246-9001 proves Seiko adopted blue Saturdays as early as 1967 - and possibly even earlier. Blue Saturdays actually stem from a societal shift in the early 1960s, when Japan began transitioning away from the traditional six-day work week.

Specifications:

The Condition: In very good condition overall. Just serviced. The hammered surfaces are in beautiful condition, and the watch is completely unpolished. The flat, unhammered sides are marked. A small piece of the gold medallion has fallen off. 

Scope: No box or papers

Movement: 5646A Automatic with Quickset and Dual Languages

Dimensions:

• Case Width: 35.5mm
• Lug to Lug: 40.3mm
• Case Thickness: 10.1mm
• Lug Width: 18mm