After the great war ends.. * all credits below
Japan was allowed to jump start its industry, with a lot of help from the Americans, Seiko did well for itself and profits culminated early on in two watch factories, Suwa and Daini-Kameido-Tokyo (Daini).
Super, Marvel and Cronos
Soon Seiko's primary watch around 1950 was the Super, a Suwa product with a sweep second hand to indicate a running movement and precision. The Super calendar, the AutoDator (not a typo), even had a fourth hand pointing to an inner date ring (so no window). At that time the competing Daini division came out with the Unique, very similar in design. Movement numbers were not used at the time and would be difficult to list at any rate as Seiko was continually refining to get up to Swiss standards. As things go next up was the low beat 'Marvel', from Suwa again in 1956. It was furnished with 17, 19 or 21 jewels - at different price points. Its auto-wind capability however was such an innovation that all kinds of indicative names were put on the dial for decades to come (and even today are slavishly added on for no other reason than historical inertia). Seiko called it the 'Gyro Marvel' and bestowed a movement number: caliber 290. It was however only produced from 1956 until 1959.
Like clockwork the Daini design team soon followed suit with the Cronos in 1958 using caliber 54A - it being thinner than all that went before (a recurring Daini theme) with a full 'bridge' anchored at both ends holding the balance wheel, with the Diashock technique applied. Somewhat later in the competition the 810 Cronos Special in 1962 was released
First King and Grand Seiko
Suwa and Daini competed furiously with leaps and bounds and with a spectacular array of watches. In 1959 the 'Crown' saw the light of day (well sometimes) with caliber 560, and immediately afterwards using this as base the 3180 Grand Seiko in 1960. Quite impressively the 5720 Grand Seiko also came out with 25 jewels, followed by the 5722 calendar with a whopping 35 jewels in 1963. All these movements were manual wind and just stepping stoes it seemed as in 1961 already Suwa introduced the 57A and B versions of the Crown as well as the 5760 Special and the 341 Special. These models had different levels of finish and price points to allow for consumer choice.
Eventually Seiko made no bones about it any more and just presented the new Daini only King Seiko, to be in direct competion with Suwa's Grand Seiko (also made by Daini). Only the 56xx's would be used henceforth by Suwa in the Vanac line for example.
Of course Seiko always juggled around with its product lines and it came as no surprise that the high-end but short lived Goldfeather, caliber 60A, was released in 1960 in 17 and 25 jewel versions.
Suwa's next watch in 1960 was the Liner, with movement 3140 (also known as 620). It again being the basis for the later 62XX Seikomatics. In 1963 the Liner Chronometer featured movement 6240 (also known as the 460). None of these watches had hacking capability and among those that were automatics, none were also manual wind.
The first Seikomatic was the 6201--the next automatic after the Gyro Marvel. The 6201 is basically the 'Liner' with auto-winding added on, similar to the way the Gyro Marvel evolved from the Marvel. In 1961 the 6601 Sportsmatic was another automatic. Other existing 3-digit movements seem to have been incorporated into the 62x Seikomatic line.
The Sportsman also came out of Suwa in 1960: movements 175, 436/4361, and 66, then the 957/6602 calendar (year unknown). This may have been the predecessor to the Sportsmatics, and indeed the 957 became the 6602, and the 66XX series was the Sportsmatic series.
An Era of Rapid Innovation and the Ascendancy of Suwa
Suwa introduced the 402/6220 'Skyliner' was introduced in 1961. They followed up with the 956/6222 'Skyliner Calendar' (non quickset date), apparently in the same year. The Skyliner moved on to the 61A and 6102 in the late 60s, which were the movements used for the edgier-styled Skyline models.
The 6201 Seikomatic and 6220 Skyliner in 1960 and 1961 seem to be the genesis of the 62xx series. This series has so many notable movements. 1962 seems to be the beginning of a rapid acceleration in the number of different movements and models. There has been debate about whether the 35j 6218 was a dry run for the 6245 GS (same jewel count, different fine adjuster type, and different calendar, with the 6218 being D/D and the 6245 date only). It seems more likely that the 39j 6216 was a dry run for the 6246 GS. The 6218, in turn, seems to be an improved version of the 6206, which itself is a revision of the 400. [Source: http://www.h4.dion.ne.jp/~smatic/]
The 6201 series underwent a series of evolutionary steps in the early 1960s. In 1960, Seiko introduced the 6201 Seikomatic (previously known as the 603 movement). In 1961, they introduced the 6220 Seikomatic (previously known as the 402). In 1962, they released the 6205 Selfdater (previously 394). In 1963 they came out with the 6206 Weekdater (previously 400) and 6240 Liner (previously 460). In 1964 came the 6218 'Seikomatic' and 6217 'Silverwave'. In 1966 we saw the 6245 and 6246 Grand Seiko. In 1967 they introduced the 6215 300m diver. We also saw the 6222 (previously 957) 'Skyliner Calendar' and 6216 39 jewel (previously 395). Whew!
62XX Notes: Many, if not all, of the 62xx movements were hacking, but none were handwind-capable and among those with a day of week, none offered quickset on the day of the week. The 6222 Skyliner was not even quickset date. The 6216 and 6218 had both the dolphin and crown logos on the back. The 6216, 6245, and 6246 movements have rack & pinion fine adjuster, while the 6218 has the tadpole.
In parallel with the 62xx series, Suwa also developed the 66xx series, which boasted the 'Sportsmatics' and were the first watches to be marketed as 'Seiko-5's. The 66XX movements are slightly thicker than the 62XX'ss. The 66XXs were also not hacking, handwind-capable, or quickset.
In 1963, Suwa developed the 83XX series. This new series was similar in many respects to the 62XX series but with a focus on thinner movements. Some of these may have been reworkings of the 62XX's. The reworked versions were known as 'Seikomatic-R' with the 'R' presumably meaning reworked. The 83XX line was comprised of the 8305 (was either the 830 or 840), 30 Jewel Slimdate, the 8306 30 jewel Business/Weekdater (often bearing a Sealion logo), the 39 jewel 8325, and the 27jewel 8346.
Throughout the late 1950s and early 1960s, the Daini plant seemed to be able to produce equivalent-quality products to those of their sister plant, Suwa. However, the 76XX series, developed in 1963-64 was arguably a lower quality product group. This line included the 'Champion' and the predecessors to the DX models. Then, nothing new came out of Daini until the 1967 51XX series. They then went quiet again until the early 1970s, when Daini released the 70XX series. The 70XX movements were known for being chronographs with a flyback complication that was similar to the Suwa 6138/39 chronographs. This is probably because Daini had chief responsibility for ladies movements, and indeed there is a plethora of 2xxx ladies movements in the 60s.
The 'Champion' was a mid-grade movement when compared to Suwa's high-end 'Cronos'. Throughout 1963, Suwa evolved this movement through the 850, 851, and 7622 (860) versions. One of these models was known as the 'Flying Fish'. Daini also produced a 'Fairway 760/61' in 1962 with both 17 and 21 jewel movements. They later followed up with the 820/7625 Sportsmatic Calendar in 1964, which was the final model in the 76XX series.
Also in the early 1960s, Suwa developed the 57XX series. These models were produced at the same time as the 62XX and 66XX lines. The 57XX is a bit of a hodgepodge. The line included the 5720 Grand Seiko from 1960, the 5760 Crown Special from 1961, the 5722 Grand Seiko from 1963, 571X hand-wind chronographs from 1964, and the 5740 'Lord Marvel', which came in lo-beat (18k, 5740A/B, 1964) and hi-beat (36k, 5740C, 1967) versions. Internally there may be some relation between all these different 57XX movements, but it is not readily apparent.
The final series from the 1960s is Seiko's 44XX movements. These are high-end hand-wound movements. They are descended from the earlier King Seiko model. They were mostly produced from 1964 to 65 at the Daini plant.
The Product Lines Mature, and the Continued Dominance of Suwa
The Seikomatic and Sportsmatic lines were retired in 1967. They were replaced by the thinner workhorse 61XX movements, which were used in everything from the 6102 'Skyliner' and 6106 dress watches, the 6117 'Navigator' and 'World Timer' watches, to the 6105 'Diver', to the 6138/39 chronographs, as well as the 6145 and 6156 Grand Seiko. They were also used in the 6185/86 Grand Seiko VFAs, and the 6159 300m and 600m divers. Suwa produced three different 'tiers' of Grand Seiko: the "standard" Grand Seiko (2A) in calibers 6145 & 6146, the 'Special' (3A standard) in calibers 6155 & 6156, and the 'VFA' (4A) in calibers 6185 & 6186. The 3rd digit of the caliber number was used to designate the accuracy standard which the movement conformed to. The 4th digit determined the type of display (5 = date; 6 = day/date). According to the tech manuals, most or all of these are derived from the 6106 as the base movement. At the same time, Suwa developed the 4005/06 Bellmatic.
In fact, at around this point, Seiko seemed to have made the first serious effort to standardize their movement numbers. Her we see the first two numbers as the 'base'. The 3rd digit signifies the grade of movement (so a 6246 is higher than a 6206). The 4th digit indicates the date display type: 1 = no date, 5 = date only, 6 = day and date).
During this time period, Daini developed the 51XX series, which includes the 5106 (1967) and 5146 Presmatic (1969), but also some Seiko 5 DX movements, the 23 jewel 5126 and the 27 jewel 5139. There is also the 5106 'Weekdater' and the 5105 and 5125.
In 1968, Suwa developed the 56XX high-end movement for the King and Grand Seiko lines. The King Seiko saw the addition of the 'Vanac' and the 'Lordmatic'. The Grand Seiko saw the introduction of the 5641, 5645, and 5646 watches in 1970. Daini followed up with the competitive 52XX series starting in 1969. The new Daini movement immediately became the new standard for the King Seikos for both the 'Vanac', and 'Lordmatic' watches. Both the 56XX and 52XX movement series had hacking, auto-winding and quickset features. The Daini 52XX later became the 4SXX series. The Suwa Lordmatic (56XX) is manufactured to the Seiko "C" accuracy standard while the Daini Lordmatic Special (52XX) is "B" standard and runs at a 28,800 b.p.h. beat rate (Suwa Lordmatic is not "high beat" - probably only 21,600 b.p.h.).
In parallel with the 52XX series, Daini also developed the high-end handwind 45XX King Seiko/Grand Seiko series. The VFA version of the 45XX took 2nd place in the Swiss Neuchatel chronometer competition. It is possible that the engineers at Daini were given responsibility for developing movements for the Swiss competitions. This would explain their lower productivity in terms of new movements, as well as the various VFAs from Daini.
It is important to note that the Daini 45GS "VFA" models 4520A & 4582A that were entered into the Swiss observatory contests were not "production" VFAs, but specially constructed models with accuracy & performance standards that differed from the "4A" (men's GS VFA) standard. Quite clearly the Grand Seiko VFA had a "Daily Rate" of -2 to +2 seconds while the Astronomical Observatory Chronometer used was only -8 to +8.
The Advan line, which appeared about this time, were "mid grade" modernistic style watches produced with 6106, 7019, & 7039 movements (thus being made by both Suwa and Daini divisions). There could be though of as 'mid quality Vanacs'.
The Ascent of Quartz
The 6306, 6309, and 700x in the 1970s seem to have been the last mainstream mechanical movements. 630X were Suwa. 70XX were all Daini. The TZ movement table must have an error here: it lists the 7006 as Suwa, even though it was the base movement for the 701X movement.
At this point, Seiko was shifting heavily to quartz, and except for the divers, it seems they stopped making mechanical watches entirely until the 1990s. They certainly had a number of firsts in the meantime, with the first quartz on the market, the first quartz chronograph, and I think the first watch with an IC (was this the 6M series)? Later came the Kinetic (autowind mechanism to charge a capacitor to drive the quartz movement) and most recently the Springdrive (mechanical, with a quartz oscillator to check the rate--charged via a Kinetic-like mechanism).
As most Seiko watch afficionados know already, around 1962 or 1963 Seiko standardized its movement (case back) numbers for existing and new calibers considering the continued expansion of the brand and a plethora of product line experiments.
The sequence used of four digits dash four digits was eminently logical and frankly the best in the watch world bar none. It allowed Seiko to structure its catalogs for decades to come.
In general the first digit remains a mystery as to what it signifies, the only thing that can be said is that the Suwa division used 6 and Daini 7 - but later on this was let go. Of course there was tendency to keep numbering up for later product line movements.
Digits three and four are more informative fortunately, indicating respectively the quality grade of movement and the whether there is a day or date complication, or none. Make an educated guess now: 6201, 6205, 6246.
Sadly the Seiko numbers don't always add up.. There is a similarity between the 6206 and the upper echelons of 62xx, but to what degree? There is also some continuity apparent, but the 6201, 6220 and the 6222 seem to come before the 6206, so how can the 6206 be the base caliber for the 62XX series? It goes on, the 6606 and 6619 appear related mechanically, but the other 66xx are not. In all Seiko seems consistent but often isn't.
The following movement standardization list circulates online (particular source a bit vague as it stands) and has been fairly complete for a while now.
2451 Sportsmatic, 1961, Suwa, aka the 245
3140 Liner, Suwa, 1960, aka the 620
4361 Sportsman, Suwa, 1960 - before cal. 66, aka the 436
5700 Crown, Suwa, 1959, aka the 560 and 57A
5722 GS, Suwa, 1963, aka the 430
6200 aka the 603
6201 aka teh 603 but with automatic winding
6205 Seikomatic Selfdater, 24j, 1962, Suwa, aka the 394
6206 Weekdater, Suwa, aka the 400 (modified though)
6220 Skyliner, Suwa, 1961, aka the 402
6222A/B Skyliner Calendar, 21j, Suwa, aka the 956
6602 Sportsman Calendar, 17j, Suwa, aka the 957
6606 Sportsmatic 5, Suwa, 1963, first 5 date, aka the 410
6240 Liner Chronometer, Suwa, 1963, aka the 460
7622 Champion, 17j, Daini , aka the 860
7625 Sportsmatic Calendar, 17j, Daini , aka the 820
8305, 8305B Seikomatic Slimdate, 30j, 1963, Suwa, aka the 840
8325A Seikomatic Calendar, 39j, 1965?, Suwa, aka the 395 (the 395 has no fine adjuster)
8301 Seikomatic Slim, 30j, non-calendar, Suwa , aka the 830
The original version of this article was written for the Seiko Citizen forum in August of 2006 by 'Kwahoo'. Thanks to Christopher Huang for helping me locate the original. Kwahoo stopped posting on that forum in 2009. Kwahoo listed a series of sources for his work, but sadly almost all of those links are now dead. The one remaining one is listed below, but it is in Japanese.
This article was modified from the original text to present the information in more of a textbook form with much of the conjecture and 'head-scratchy' text removed. It does refer to "A Journey in Time" which is a freely distributed text (written by Seiko Corporation staff) which we host a copy of locally. I hope Kwahoo is doing well and appreciates this homage to his efforts.
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