Does Seiko serialize their movements?

[rfortson]

As the title says, does Seiko put a serial number anywhere on their movements?  I've only opened a few Seikos, but I never saw an obvious serial number anywhere, like on most Swiss watches.

The reason I ask is that I saw a watch for sale which had a "Proof" dial, but then the caseback serial number indicated mid 70's.  So something was changed, either the caseback, the dial, or what, I don't know. 

So, for you watch mechanics here, have you seen serial numbers on Seiko movements?  And if not, how do you go about figuring out if the watch is comprised of all the original parts and not put together from various watches of the same style/era?

[igniferroque]

They did (do?), but only on higher end movements. With the low end stuff you have to rely on minuscule differences to help you date the parts.

[rfortson]

Thanks, that's kind of what I was figuring, but thought maybe there were serial numbers buried deep inside somewhere.

[cobrajet25]

Feb 18, 2015 9:24:06 GMT -8 igniferroque said:

They did (do?), but only on higher end movements. With the low end stuff you have to rely on minuscule differences to help you date the parts.

[Rod]

An example of a numbered movement! But, the number does not match the production number. So the only way you can be sure is to have the certificate for that watch.

 

As can be seen with this one of mine the tag has the movement number on it, which has no bearing to the case number which is in this case D4xxxxx (Dec,1964)

[cobrajet25]

When Seiko makes major changes to a movement, they will usually change the designation of that movement.  For example, the 6106A will become the 6106B.

If you know about when these changes took place, you can get a rough idea of when the movement was made.