Understanding Seiko model numbers

[Estoril-5]

As the title says, is there some linking of the model number​ to the watch spec?

Some watches look similar but have different model numbers.

And then there's names which I've never heard of and unsure how they came about e.g. BFK, tuna, monster or Spork etc.

Can anyone shed some light on this or even point me in the right direction to do some reading.

Cheers

Sent from my Moto G (4) using Tapatalk

[S.L]

My understanding is that there is little apparent logic behind the model number designations.
Typically the only consistwncy seems to be that they begin with a "S" as in Seiko (SRPxxx/SBBNxxx/SARBXxx/etc) and odd numbers designating a SS only case/bracelet.
But if there is more to it I'm happy to learn.

Nicknames tend to happen mostly by the power of forums but I have never seen anyone that has catalogued the background for each, must be quite a task to get sorted.

[Der Amf]

At the bottom of a Seiko dial and usually on the caseback too is an eight digit code. The first four tell you the movement, the second four tell you about the style of the design.

For example, I've a 7000-8000 from 1971. The 7000 was the most basic movement in the 7xxx series from which the 7s26 evolved - no date, no hacking, no auto winding. The 8000 tells you that the watch is very plain - a simple dial with stick indices in a simple case.

I've also got a 6100-8000 from 1968. Using the above information you can gather that it has a datefree, manual version of the 61xx movement and has a plain dial with stick indices in a simple case.

I've recently bought a 6206-8080. The second 6 tells you that it has both day and date windows, and the 6080 tells you that the dial isn't entirely plain. I can't translate that bit any further. Sometimes the caseback number isn't exactly the same as the dial. Again, I can't give the explanation for that.

[markrlondon]

There are (1) Seiko model numbers, (2) nicknames, (3) movement references, (4) case references, (5) dial references, and (6) strap/bracelet references.

(1) Model numbers

- A model number is the specific reference number given by Seiko to a specific watch with a specific combination of movement, case, dial, colour, finish, strap/bracelet and so on.
- An example of a model number is SKX009K2 (which refers to the classic SKX009 diver's watch with dark blue dial, pepsi bezel, on jubilee bracelet).
- Another example is SKX779K1 for the first generation Monster, with black dial, on stainless steel bracelet.
- In discussion it is common for model numbers to be abbreviated to just the first section, such as SKX009.
- The suffix (e.g. K2 in the first example above) usually differentiates type of strap or bracelet and/or intended market or manufacturing location. The SKX009K1 is on a rubber strap. The SKX009J1 is on a rubber strap and is labelled 'Made in Japan'. Other suffixes are P1, P2, and others. I've never identified a truly consistent meaning to these suffixes between models.
- Model numbers appear only on hang tags and in catalogues. The model numbers do not appear anywhere on the watch, in manuals, or on warranty cards.
- Model numbers are often lost to history for many models and we end up using only the movement-case references (see section (4) below).
- So in summary a model number designates the particular combination of movement (see section (3)), case (see section (4)), dial (see section (5)), bracelet or strap (see section (6)), and all other features that make a particular model of a watch unique.

(2) Nicknames

- Nicknames are almost always the product of forums.
- Examples:

- Oddly for such a popular watch the SKX009 doesn't seem to have a nickname.
- The SKX779 is the Monster (first generation with 7S26 movement).
- The nickname Monster is also used for second generation Monsters using the 4R36 movement and for other similar watches.

- I think Seiko has named a few special edition watches but they don't seem to give most of their watches names, just model numbers.

(3) Movement references

- Obviously each watch has a movement and this is referred to by its movement reference.
- For example, both the SKX009 and SKZ779 Monster use the 7S26 movement.
- The movement reference is combined with the case reference to designate a particular case design and with the dial reference to designate a particular dial design: See sections (4) and (5) below for more information.
- Movement references are four characters codes (e.g. 7S26, 4R36, 8F56, A914). In the past, two character codes were also used (e.g. 66).

(4) Case references

- Each case design has a unique reference number.
- Case references are four character codes, e.g. 0020, 0350, 5A09.
- The movement reference is combined with the case reference to create a full case reference (commonly referred to simply as the 'case reference' or 'movement-case reference').
- Examples:

- 7S26-0020: This is the SKX007 or SKX009 movement and case.
- 7S26-0350: This is the first generation Monster movement and case which has many model numbers depending on dial and bracelet/strap combination (e.g. SKX779xx for black dial models and SKZ781xx for orange dial models, where xx is the suffix as described in section (1) above).
- A914-5A09: This is a 1984 stainless steel cased LCD digital watch, the model number of which is unknown (do let me know if you know it).

- Except in very rare special editions, the movement-case reference is always displayed on the case back of the watch or on the rear of case next to the case back.
- It is the movement-case reference that is used to identify a watch on its warranty card and also to identify spare parts for the watch.

(5) Dial references

- In the same way that each case design has its own unique reference, each dial design has its own unique reference.
- The movement reference is combined with the case reference to create a full dial reference (commonly referred to as the 'dial reference' or 'movement-dial reference').
- Examples:

- 7S26-002R R 2: This is the dark blue dial of the SKX009K2.
- 7S26-2084 R 2: This is the black dial of the SKX779K1 Monster.
- A914-5A0A NT: This is the 'dial' of the A914-5A09 LCD digital watch.

- I have never seen a modern Seiko watch that does not have the movement-dial reference displayed on dial of the watch at the bottom.
- Movement-dial references tend not to be discussed as much or be as well known as movement-case references.

(6) Strap/bracelet references

- Straps and bracelets also have their own reference numbers.
- These do not seem to be so consistently displayed as movement-case references or movement-dial references.
- Examples:

- 44G1-Z·I: Jubilee bracelet used for SKX007 and SKX009 (with appropriate suffixes). Other versions of the SKX007 and SKX009 are supplied on rubber strap or oyster-style bracelet.
- 49X8-G·C: This a Monster-style bracelet for the first generation bracelet Monsters (SKZ779, SKZ781, and others with appropriate suffixes). Other Monster version are supplied on rubber straps.

- Note the middle dot used in the references. The character appearing after the middle dot may be a revision identifier.
- I think the middle dot is Unicode character U+00B7 Middle Dot.
- It is possible in some cases that watch model numbers may not have been updated when the revision identifier of supplied bracelets was updated.
- Leather and rubber straps also have references.

Simple, eh?

Errors and corrections gratefully received.


** edit **

Two more comparative examples:

Model Mumber	Movement Ref	Movement-Case Ref	Movement-Dial Ref	Strap/Bracelet Ref	Description
SPC123P1	7T86	7T86-0AC0	7T86-0AC8 HR 2	Bracelet: MOEV·D·W (Bracelet end pieces labelled 214)	Quartz chrono, perpetual calendar, alarm; stainless steel case; Hardlex crytal; silver modern-style hands; silver-white batons dial; stainless steel bracelet
SPC131P1	7T86	7T86-0AC0	7T86-0AD8 R 2	Leather Strap: ref unknown	Quartz chrono, perpetual calendar, alarm; stainless steel case; Hardlex crystal; blued feuille hands; white arabic numerals dial; leather strap

[Leiwu]

I'm not sure, but I saw similar information on their website, somewhere in the history section
But still, the work done is impressive really cool. very clear
I also found cool information about their history here: https://www.bestadvisor.com/seiko-watches
Maybe someone will be interested