Seiko 6138 Kakume Reference Guide

Last updated on: March 31, 2020

The acquisition of a Seiko Kakume (also known as Square Eyes) back in the day is partly responsible for my interest in vintage watches and was the beginning of my romance with the Japanese brand. Just like the UFO, its design is unique and still very relevant today, 50 years after its release.

Like other Seiko 6138 chronographs, examples of Kakume’s in good condition are becoming increasingly hard to find, and there are more and more watches equipped with aftermarket parts. In this collector’s guide we’ll go through dial and hands variations. Let’s get ready to add a perfect 6138-003X to the collection!

Seiko Kakume: the ADN

Name and size

Kakume means “square eyes” in Japanese and it’s easy to see why it was dubbed this way: the square sub-dials give this model a very special look. Some collectors also refer to this model as Big Blue. Indeed, the case is big, coming in at 43mm in diameter. Furthermore, the watch is thick: around 15mm. When you wear a Seiko Kakume, you rarely forget that the watch is on your wrist. In contrast to its impressive dimensions, the lug width is rather modest: 18mm.

Model numbers

The following model numbers can be encountered:

  • 6138-0030
  • 6138-0031

The vast majority of watches you will find will have the model number 6138-0030.

6138-0031 are rarely seen. It seems like this model number was used at a later stage as I’ve only seen it on watches with blue dials manufactured in 1978.

Release date and retail price

I have the impression that the Seiko Big Blue began its run somewhere around 1972/1973 as I couldn’t find it in early catalogs. This is consistent with my caseback observations: I’ve only seen watches with manufacturing dates between 1973 and 1978.

In terms of MSRP, I found two prices, both in Japanese yen: 21,000 and 23,000 (if you know the RRP in $, please let me know in the comments area). What’s funny is that both of these prices appear in the same year catalog (1974), but in different volumes (vol. 1 vs vol. 2). In all other catalogs, the retail price is 23,000 yen, so let’s consider this as the more correct one.

23,000 yen was equal to roughly $80 back in the day. Taking into account inflation since 1974, this corresponds to 55,000 yen and $435 today.

Kakume in the catalogs

You will find below all the catalog images of the Kakume that I could find. Unfortunately, for some of them, the catalog year is unknown.

How to buy an authentic Seiko 6138 Kakume?

Let’s dive in and see what you need to pay attention to when browsing eBay and forum listings featuring the Big Blue (or Big Champagne? as we will see later, there was a champagne-color of this watch too!).


This Seiko watch is powered by one of the most famous automatic chronograph movements: the 6138. Released around 1970, this movement has a manual winding feature, boasts minute and hour registers, and displays the date and the day of the week. Very advanced for its time! This movement had two variations – the 6138A and the 6138B with a modified switching mechanism. The 6138A has 21 jewels and the 6138B either 21 or 23 jewels.

All the watches that I had the opportunity to inspect were equipped with the 6138B, 21 jewels movement:

Seiko 6138 Kakume movement
Movement from a watch with a JDM early blue dial (1973)

Dial & hands

Blue dial

Kakume dials came in two different colors: blue and champagne.

Blue dials may have the following markings at 9 o’clock under “Seiko”:

  • “Chronograph Automatic”: this is the international version.
  • “5 Sports Speed-Timer”: this is the “early JDM” (Japan Domestic Market) version.
  • “Speed-Timer”: this is the “late JDM” version.

You may have noticed some subtle differences looking at the watches above besides the markings at 9 o’clock. Here are my findings:

  • On the international version, the day/date frame is black, whereas it is white on the JDM versions.
  • The Big Blue can come with arrow hands (first watch above) or with baton hands like on the other two watches. International versions always come with arrow hands. JDM versions usually have baton hands. However, early JDM dials can also be encountered with arrow hands.
  • Most of the time, the sweeping hand and the sub-dial hands are orange / red in color, but they can also be yellow.
  • Dial design slightly changes depending on the set of hands the watch comes with:
    • Arrow hands: there are lume points at 6 and 9 o’clock and a double lume point at 12 o’clock. There are also small lume points at the end of hour markers.
    • Baton hands: no lume points on the dial. No lume on hour markers.

Champagne dial

Champagne dials were only made for the Japanese market, thus no international version here. This color is really amazing with a gorgeous pumpkin ring that is, alas, often quite faded. They can have either early “5 Sports Speed-Timer” or late “Speed-Timer” markings at 9 o’clock.

Champagne Kakume can be equipped with arrow (left picture above) or baton hands (right picture). The subtle differences regarding lume points are present here as well: if the watch comes with arrow hands, the dial has lume points at 6 and 9 o’clock and a double lume point at 12 o’clock. There’s some lume at the end of hour markers too. On the other hand, there are no lume points on the dial if the watch is equipped with baton hands.

Dial numbers

Dials have some markings between 7 and 8 o’clock, and between 4 and 5 o’clock. The first one always says “JAPAN 6138”. The second one is the dial reference number. It’s different from the number displayed on the caseback (-0030 or -0031). So far I’ve seen the following dial reference numbers:

  • 6138-0040T: blue or champagne dial, early JDM, arrow hands.
  • 6138-0044T: blue or champagne dial, early JDM, baton hands.
  • 6138-0045T: blue or champagne dial, late JDM.
  • 6138-0050T: blue dial, international.

Crown and pushers

The crown is ribbed and unsigned. The pushers taper slightly at the end.


Some of the aftermarket bezels are very well designed and it may be hard to determine whether yours is original. If “TACHYMETER” is written in yellow, then it’s aftermarket – the original one has the text in white/silver. Other than that, observe carefully the spacing and the font to assess the bezel authenticity.


The crystal is Seiko proprietary mineral glass (hardlex). Reference #340W18GN. It’s easy to get a quality replacement for ~$30 if the original crystal is scratched, so I usually don’t worry much about this. It’s generally considered that having an aftermarket crystal does not reduce the value of the watch that much.


Original bracelets for the Square Eyes are as follows:

  • Fishbone bracelet for international models. Code found on end links: Z039.
  • Oyster / H-link bracelet for JDM models. Code found on end links: XGA 261. The clasp either says “Seiko 5 Sports” (watches with early JDM dials) or “Seiko Speed-Timer” (late JDM dials).

There are also rumors of a third possible bracelet made by Stelux.


I observed two types of casebacks when it comes to 6138-003X:

  • The “horseshoe” or “elaborate” caseback, with a circle and the following markings: “SEIKO”, the Suwa sign, “Stainless Steel”, model number, “Water Resistant”, 6-digit serial number and “Japan A”. Based on my observations, these casebacks were found on first batches of watches manufactured in 1973.
  • The “simple” caseback, with similar information but organized in a different, more basic way. Observed from 1974 until the end of production in 1978.

Beware of aftermarket parts

During your search for the perfect watch, you are 100% sure to encounter timepieces fitted with aftermarket parts. Some sellers disclose it. Some sellers don’t know (let’s give them the benefit of the doubt). And some sellers knowingly replace parts but “forget” to mention it. With all the fake parts out there, pay particular attention to the dial, hands, bezel and pushers. In the gallery below, you will find a few examples of watches with aftermarket parts. Can you spot them?

Buying a Seiko Kakume: the quick checklist

Ready to buy a Kakume? Here is a checklist that you can use:

  • Make sure you have clear pictures of the dial, the caseback (with a good view on end links), the movement, the sides of the case and the bracelet clasp. Ask for additional pictures if necessary.
  • Dial: does it pass the authenticity test? Does the dial number seem correct?
  • Hands: are the hands correct for this model (arrow or baton hands)? Are they consistent with the dial?
  • Movement: make sure it doesn’t show any corrosion / rust / humidity marks. What’s the service history? Do all the functions work as expected? Does the second hand return to zero? If some of the functions don’t work (e.g. chrono doesn’t start), repair may be expensive. On the other hand, if the only issue is sticking pushers (make sure they are authentic by the way), this is no big deal.
  • Case: examine the sides of the case carefully. Are the edges sharp? Avoid over-polished cases that look like a soap bar.
  • Caseback: does it have the correct model number? Is the data readable? If it is not, the caseback may have been polished.
  • Bracelet: does the seller claim that it’s original? Check the markings on the end links to have an idea of the authenticity of the bracelet. If you plan on using the bracelet, make sure it’s big enough for your wrist, sometimes the bracelets are quite short (16-17cm).
Like This Watch?
Seiko Kakume
Seiko 6138-003X "Kakume"
Use this buying guide to purchase a legit Seiko 6138 Kakume. Make sure hands and dial match, and pay special attention to the cosmetic condition of the watch.

Wrapping up

I hope that you found this guide about the Seiko Kakume useful. Even though I tried to make it as complete as possible, I am by no means a Seiko expert – if you notice some discrepancies or have something to add (for example vintage catalogs, ads or brochures featuring the Seiko Kakume), please do not hesitate to do so and leave a comment or send me an email. You can also get in touch via Facebook, Twitter or Instagram (links in the signature below).

Further reading : check out our vintage Seiko reference guides


  1., Seiko 6138 models guide (in French)
  2., Early 6138-0030 JDM Speedtimer “Kakume”
  3. various eBay and Yahoo! auctions listings
Seiko 6138 Kakume Reference Guide 28
Vintage Watch Inc

Dennis is the founder and editor of Vintage Watch Inc. Passionate about Soviet and Japanese vintage timepieces and a finance professional by day, he proudly wears a Seiko Pogue with his suit.

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Very good discussion of the 6138-0030. I have four 0030’s and everything you’ve written is spot on. The horseshoe case back is indeed very rare. The one I have is on an early blue 5 Sports Speedtimer and dates from August 1973 with a 1 country code at the end. Mine has something you did not mention, gold subdials and date window frame. I’ve been told it started out as silver but has faded but I don’t believe that. I feel it came from the factory that way. What are your thoughts on this?