Seiko serial number - laubandrickki

How to Date a Seiko Watch

The replacement 7s26b caliber however, came out in late 2006 but the production calculator does not take this into consideration. There is considerable similarity to my recently bought SMY115 — which you gave the suffix P, which I assume means that both watches were assembled in Singapore. You also need to know the six digit serial number, with the first two digits identifying the production year and month respectively.

SEIKO - Serial Number to Manufacture Date Decoder Simple and quick, this page allows you to determine the exact date of manufacture of a basing on the caliber and serial number printed on the bottom plate or in the edge. The current SKX series 7S26 divers are harder to date using the Seiko date indicator. Caseback dating dilemma: Was this Seiko 5 Superior from January 1997 or January 2007? Limited edition Seikos are usually made within a very short time frame — perhaps not more than a few months in the year it was introduced.

Seiko Date Finder - The date of manufacture will be calculated using the first 2 digits of the serial number and my database of movement manufacture dates. For decade itself, you have to know the actual production dates of the movement itself.

In the back of Seiko watches there is a range of information presented. This can tell you the movement type, date of manufacturer, how to open the case, which company produced the product, what the case is made from and the specific case design code. These codes are also occasionally stamped on the inside of the case back while the external surface remains clean. In the article they describe the different details that were shown on the case backs at that time. Case Number: The next useful group of data is the Case Number. This is broken down into two sections; the first is a 2 or 4 digit Caliber Code movement number. This is separated with a dash to the Design Code case type. The design code is unique when used in combination with the Caliber code. For example the case number 8000 used for the 5740-8000 is a completely different design to the 8000 case used with the 6105-8000. The 4th digit in the case number is also used to differentiate the models. The last number can indicate different distribution regions or also can represent different revisions of the case design. The watch case number can be cross referenced with the Seiko JDM catalogs. You can see the design code listed below the watch. There are a pair of numbers presented inside. The first number is the case design code and the second is the dial code. Initially the catalogs did not list the specific caliber number for all models but this was introduced in the 1976 catalog. Below are some examples from various JDM catalogs. Water Proof: The obvious marking is present if the case is stated to be waterproof. This marking changed read Water Resistant or simply Water Resist in around 1970 due to legislation changes in the US market. By 1971 almost all models had changed from Proof to Resist markings. For some waterproof models opening instructions are included on the case back. This is usually for one piece cases and they will often state the external size of the crystal so you can identify which die to use in a Seiko S-14 one piece case opener. Here are the case back examples shown in the S-14 tool manual, the tool and manual can be seen. Serial Number: The serial numbers on modern Seiko models are comprised of 6 digits. The first digit indicates the year, the following character the month and the remaining 4 digits a unique production number. The month is listed as 1-9 for January to September, then 0 for October, N for November and D for December. For example on this case number of 7005-8062 the serial number is 652290. This indicates the example was manufactured in May 1976 and the unique production number is 2290. Exactly how this production number was allocated between models and production runs is not clear. As the year is only comprised of the single digit, to determine the relevant decade the model is from you need to know the period that the watch was released. This can be determined by the calibre number, as most movements were not produced for longer than a decade. For movements that were produced for a long period of time they often go through various revisions and are marked with a version letter like A, B, C etc at the end of the general calibre e. The six digit serial numbers are found on Seiko models beginning from 1966. Previous to this Seiko used a seven digit serial number with a similar format. This seven digit serial number continued until 1969, so there is a transition period where some models had a six digit serial and other models a seven digit. While most of the seven digit serial numbers followed the Year, Month, Production format there are some examples that seem to follow a Month, Year and Production format. If you want to confirm the production date on a specific model there are a number of online calculators available. You just enter your watch serial number and caliber number and the date will be calculated. A comprehensive date calculator can be found here -. There are some error on this site but in general it is quite reliable. Case Manufacturer Code: The final item on the case back is the country and case manufacturer mark. On the 7005 example above it is listed as Japan-G, but there are numerous other case manufacturer codes. The most commonly seen are Japan-A and Japan-J but Japan-X and Japan-S are also seen. It is not clear if these codes directly relate to a case supplier e. Japan-J can indicate a different manufacturer for model A vs model B. The case back format described so far continues today with the same general format but there has been a change in the layout and some additional information added over time. Case Construction Mark: One of the additional items added to the case back format was a case construction mark. Initially this was an additional letter that was included at the end of the case number and later moved to waterproof section. The first character indicates the basic construction of the case and if present the second digit represents the deviation from the standard construction. Details of this case construction mark can be seen in the 1982 Seiko Case Servicing Guide. Magnetic Resistance: Another case marking that has been added to some watches indicates magnetic resistance. This is represented as a horseshoe magnet and can have either a single or double bar under it. The single bar indicates standard magnetic resistance while the double is for enhanced resistance. Battery Change Index: On many Seiko quartz divers there is an outer series of markings that are there to indicate when battery changes have been made on the watch. The markings will indicate the year number and this is divided down into quarters. When the battery is fitted at the factory the first suggested battery change time will be marked on the case. This is shown as a round punch mark above the relevant quarter of the year the change is expected to occur. Service Battery Markings: On some divers there will be a five character stamped code on the back. These marks are often incorrectly identified as some kind of military marking or similar but a much these are due to a much simpler explanation. Once the years indicated on the battery change index has expired Seiko service centers will often stamp the case back when the new battery is exchanged. This is done in the format BYYMM, where B stands for battery, YY indicates year and MM indicates month. You can see multiple markings on a watch that has undergone multiple battery changes. This watch is water resistant. It has a case construction code of G and is made from stainless steel. The case came from manufacturer A and is fitted with a 0903 caliber movement in a 8110 design case. The serial number indicated it was produced in October 1976 and has a unique production number of 7536. The watch was produced from Suwa-Seikosha. The watch is water resistant. It is made from hard stainless steel with a hardness value of approximately 450 with a stainless steel case back. It came from case manufacturer J and has a 9923 caliber. The case design code is 701A and it has a case construction mark of G1 indicating the first variation of a G type case. The serial number indicates a September 1979 manufacturing and has a unique production number of 0742. It was produced by Suwa-Seikosha.

Needing a watch to use during his pre-flight training, Col. The calculator doesn't have any problem with new watches or specific models for that matter it doesn't seiko serial number use specific model information and can't tell you what model you are entering. Seiko Watch Corporation has been designing and manufacturing quality watches since 1881. The 6309 movement came out sometime in 1976 and those that were manufactured before 1984 were made in Japan. Her work can be found on Overstock. The first digit only signifies the year number in a certain decade 10 years. Type II: Display backs on higher end models: In more expensive Seikos with glass display backs like the Premier 6R20 pictured above, the serial number is usually found engraved along the rim of the caseback. Good eye to catch this err on my part Cheers Leon Josch: Your statements about the accuracy of the date calculator, as it pertains to new watches is not exactly accurate. By continuing to browse our site you agree to our use of data and cookies. Is there some way I can find out?.