It stands for "my domain is shorter than your domain"

Seiko watch movement, Part 1


Nicholas Hacko, an Australia-based master watchmaker, is in the progress of publishing a fantastic tutorial on the inexpensive, ubiquitous Seiko 7S26 automatic watch movement. The tutorial is a guided stripdown and rebuild of the movement with the goal of learning what makes watches tick. I am attempting to follow the tutorial and post some pictorial status updates here.

I’ve ordered those tools recommended in Nick’s tutorial that I didn’t already have. Most have already arrived from faraway lands courtesy of eBay, but I’m still waiting for a couple of things. It turned out I only needed a couple of inexpensive additions to my existing tool collection. And I was long overdue a screwdriver set anyway!

Please note: this is not a tutorial! I have no idea what I’m doing. For all I know I could be on my way to destroying the movement. I am merely documenting my own learning process as I follow the actual tutorial.

The Seiko SNK805K2 (7S26-02J0) on my wrist. I paid £40 for this watch on eBay. Provided I can put it back in working order in the end, and learn something in the process, that’s not too bad.

Seiko SNK805K2 (above) along with the SNZG15J1 (using the 7S36 movement). The former looks quite a lot smaller in real life.

The case back unscrews with ease. I need to scrub my fingernails.

Removing the winding stem.

With the winding stem removed, the movement just lifts off.

Movement out of its case. Considering the low cost of the movement, I rather suspect this is the first time human hands have touched it.

The movement in its holder.

The movement in the holder. Still running!

That’s it for Part 1. In Part 2 I’ll start disassembling the time display parts.


  1. Great photos – I have one of those green dialed 7s26 watches too. Maybe I’ll follow you! Keep up the good work (I’m a novice too, in Atlanta, GA).

    Kind regards.


  2. Pingback: Just received my first automatic Seiko (SNK789K). - Page 2

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