Seiko Sales – January 1966

One of the key aims of this site is to be a source of information for those who collect vintage Grand Seiko. We don’t just list the watches that we have for sale in the anticipation that customers will add them to their collections – we also list watches that we have never had in stock, along with as much data about those watches as we can glean. The intent is to be a reliable source of information about exactly which references were created by Grand Seiko, and to provide data on those references.

We are confident that currently this site contains the most complete, accurate and detailed information on the historical Grand Seiko references that you will find anywhere.

Seiko Sales January 1966

Much of the information regarding vintage Grand Seiko references that you will find on this site has come from extensive and detailed research into the official publications that Seiko produced during the vintage Grand Seiko period.

The monthly newsletters that Seiko distributed to their dealers are a vital source of information. They – along with the annual catalogues – not only provide evidence for what actually existed, but can also be a rich source of data about those watches.

Currently we have close to one hundred issues of these newsletters, including the particularly fascinating January 1966 issue that came into our possession recently, and that we share scans from here.

Seiko Sales, January 1966, page 16

The issue contains a six page article that goes into some detail regarding the manufacturing and testing process that the Grand Seiko Self-dater, or “G.S.S.” for short, underwent.

The “Self-dater” was the name given to the second series of Grand Seiko that followed the “First”. It comprised of a number of different references that were manufactured from 1963 through to 1967. The first appearance in an official Seiko publication of a watch from this series was of the 43999 (SD dial variant) in the February 1964 issue of Seiko Sales, and the last was of the 5722-9991 in volume 2 of the 1968 catalogue.

One detail of particular interest to note in this publication is that whilst the watch shown at the top of the first page of the article is the AD dial variant of the 43999, the back cover of the magazine features the 5722-9990. Note that both references are shown with the earlier coarse-knurled crown.

Unfortunately it seems beyond the capability of Google Translate to accurately interpret much of the Japanese text in this article, but you can get a sense of production process, from checking manufacturing tolerances of individual parts – as seen at the bottom of page 16, all the way through to the 15 day chronometry testing regime that is detailed on page 21 (complete with photographs of the temperature controlled chambers for testing the watches at 4, 20 and 36 degrees Celsius).

Testing chronometry performance at different temperatures

The final image on page 21 shows a lady filling out the chronometry certificates. It is extremely rare to come across an example of a 57 series Grand Seiko with its original papers, but we do have one available for sale, which you can read about here. We wonder whether the very certificate that accompanies that watch is in the stack of certificates shown in this image!

Completing the chronometry certificate for a Grand Seiko Self-dater

There is no doubt lots of interesting information to be gleaned from this article. Whilst Google Translate does struggle in many places, it is intriguing to see detailed the famed reinforcement of the hairspring of vintage Grand Seikos that improved isochronism and reduced timing differences when the watch was in different positions.

Reinforcement of the hairspring to improve isochronism

On the left a diagram of a Grand Seiko hairspring, with the arrow indicating the location of the reinforcement, on the right, a regular hairspring. Note to watchmakers – if you see a hairspring with some material here, it is not dirt – do not clean it off!

If anyone is able to translate more sections of this article that provide fascinating detail, please don’t hesitate to let us know in the comments section.


Below we present an image gallery of scans of the front and back covers of the January 1966 issue of Seiko Sales, along with the 6 page article on the production process behind the Grand Seiko “Self-dater”.

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