# Seiko Dual 12h 24h mode original quartz model 8M18-9000



## Afka

When I first saw this watch on a bay I really didn't know what to do. The seller didn't know nothing about this watch, even not the model number. According to the only picture there I decided, that this must me some strange dual mode watch, which has both dials - 12h and 24h - and usually you can switch between them and pick up the mode you like more. For sure I paid too much, but it was so challenging... I was right.










I got today this watch, new, unused, in a original Seiko box, but no papers. Therefore the same old problem - where I can get information how to set this watch up. Browsing in the web shows, that this watch is rare and almost nobody knows how to manage it. Even in Seiko and Citizen forum _thewatchsite _is only one entry on this watch - question without the right answer. Now the watch is set and running and I would like to help others a little bit.

First, I can't find 8M18 user manual. You can easily find 8M15_8M18 technical manual, but it doesn't help much to understand how to set the watch. I got help from another user manual for 8M25 
http://www.seikowatches.com/support/ib/pdf/SEIKO_8M25_8M26.pdf


The setup is a little bit different - 8M18 is a special dual mode watch, which can be run both in 12h and 24h mode - but main instructions are the same.


*A.* first reset hands to 0, according to manual section "Adjusting the hand position". 
To do this 
 1. turn crown util in the mode window appears "- 0 -". 
 2. Then pull out crown to the first click and pressing buttons on the leht side adjust both, hour and minute hand to zero. You have to move both hands into "normal" watches 12 o'clock position. For 8M18 it means set both hands to 6 o'clock on the upper dial. 
 3. Push the crown back.
*B.* Set the time. Turn crown until in the mode window appears "TIME". And then follow the manual section "Time setting".
*C.* In a similar manner you can then set date and day. This is not described in manual (8M25 has instead calendar stopwatch function). Turn the crown until the mode is "DATE". Set the hands as in time setting into correct date (use the minutes hand) and day (hours hand).


Further you can experiment with setting alarm etc.


If your settings are done, the watch will show depending on the mode you can change just turning the crown
- TIME - time on 12h scale
- DUAL - time on 24h scale
- DAY DATE - date (seconds hand) and day (hours hand)

Set to 0:







TIME (12h) - 6:31







DUAL (24h) - 18:31







DAY DATE - 3rd, Thursday


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## Afka

Here some technical details:

*Movement:* 8M18, quartz 12h & 24h retrogrades, day, date, alarm
*Case:* gold plated
*Case width:* 36 mm without crown, 41 mm lug to lug
*Case thickness: * 7 mm
*Lug width:* 18 mm
*Crystal: * flat Hardlex crystal
*Water resistance:* "Water resistant" written on the back

*New style Seiko index:* SEW002J

Links:

Spare parts catalog - Seiko - 8M18-9000 - boley GmbH
How to change battery in 8M18 - SEIKO 8M18-9000


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## JKKJ

Neat watch. It's conceptually unusual, but in an appealing way.
Thanks for the sharing the research.


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## l3wy

That's quite a watch.. any idea when was it produced?


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## Afka

djspite said:


> That's quite a watch.. any idea when was it produced?


According to the serial number it's from May, 1989.

As this is my first encounter with a Seiko 8M series watch I was looking for additional information. There are several models - 8M11, 8M16, 8M25, 8M32, 8M35, etc - all are watches with different functions you can select turning the crown. But 8M18 is the only 24h watch I found. All other 8M watches are chronographs and sports timers (soccer timer, yacht timer ...). The production started in late 80s, if I'm correct.

The watches have two motors inside driving separately the hands and this design permits to have different functions with the hands. Hands can be used for hours, minutes, seconds, days, dates etc..

Later in 90s Seiko produced several "Age of Discovery" watches with similar design.

When we talk about the affordability of this watch, then tracing the archives I found prices between $ 80 (heavily used watch from India) to $ 800 (NOS with papers from Italy).

And the main question - does it count as a 24h watch? For me it is no question, this IS a 24h watch, where the hour hand has a real 24h dial. Of course, as a retrograde it is not a round dial and you cannot use this watch as a compass.


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## l3wy

I like it 

I'd say it's a 24 hour .. but that's partly because it's so different.

I like how both scales start with 0


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## Catfishg

Just found this thread and thank you for posting the pictures! A friend of mine from the military just asked if I still had this model of Seiko since he vaguely remembered it, but had never seen anything like it. I pulled mine out just to see the model number. Seeing your pictures really brought back some great memories for me since my original band is long gone and I would never have remembered what it looked like out of the box.


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## ned-ludd

I obtained one of these recently and it came with the instructions so I have scanned the English section into a PDF.

View attachment QA-10-8.pdf


It's a great little watch and I risk running the battery down by repeatedly switching between modes just to watch the hands zooming around changing positions.


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## watchman1221

Wow, that is certainly a unique watch! Have never seen one of those before- thanks for sharing!


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## fancywatchz

Interesting watch for sure. Thanks for posting the info. Are you going to wear it around?


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## ned-ludd

I'm unlikely to wear my 8M18-9000 as a daily as the retrograde gauges are too small (i.e. just under half of the 28mm dial) for me to see the numbers without my reading glasses on. My 8M15-8000 is a better candidate as the dial is a full 360 degrees and still understandable when blurry.
I also tend to not wear gold watches; almost all of mine are in stainless steel or black PVD. I've never seen the 8M15 or 8M18 in all-stainless so in their gold finish they're mostly just for my 24hr collection.


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## carlos1

I have the same watch but in black color bands. I would like to sell mine how can I know what price is right? Thank you.


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## dj8989

that one's almost as hard to read time as mine ^ ^


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## Radlet6

l3wy said:


> That's quite a watch.. any idea when was it produced?


 I have had one from new which I bought in 1988.


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