Eastman serial numbers.

[Pura Vida]

It could be chaotic by design.  Private companies don't always like to share their numbers, while public ones love to boast the "more is better" philosophy.

And I worked for a company a long time ago that had rolls of shipping labels.  When one ran out, they grabbed a new roll (and when it was busy, they used more than one simultaneously).  Those rolls were sequential within the roll, but not from roll to roll.  Maybe I've been spending too much time down in Costa Rica, where everything has a low tech solution, LOL, but I keep thinking how manual things appear to be at the Eastman factory and totally see them using something as archaic as a roll of numbers.

[AlanSam]

I can accept the idiosyncrasies of Eastman, maybe even love them for that. But low tech doesn't mean chaotic. And they could certainly employ an alpha numeric sequence which represented all the information owners might legitimately want, without revealing the number of units output. Allocating them would require more effort than it would for the likes of Taylor with their guitars rolling off a production line. It just isn't high on Eastman's list of priorities. And I can live with that.

[pszy22]

Living in the times we've been thru for the past 18 months, it helps to appreciate chaos.

[isaacsmiff]

If there is any logic to it, I can't seem to break the serial number code.   I just bought a E20P, the CoA shows a 3-11-21 date.  The serial number is M2005121.  Seems like more or less a random number with no reference to any sort of date.

Does anyone know what the date on the CoA references?  Is it a ship date?  I bought the instrument on 3-22-21 so it wasn't in the system long.

The SN is applied at the factory in China.  The COA is filled out in Pomona CA.

Eastman used a new SN system in 2020:
- "M" signifies an acoustic guitar.
- The first 2 digits indicate the year of manufacture, i.e. "2020"
- The rest of the number is a sequential number that indicates the order of production.  Your instrument SN M2005121 would be the 5,121st acoustic instrument manufactured in 2020.

As reference points, for the two Eastman acoustic guitars that I purchased in 2020:
SN M2005805 - Shipped from CA on 08/12/2020
SN M2018210 - Shipped from CA on 12/22/2020

Based on this, your guitar was probably manufactured around June -July of 2020.  

On the older COAs, the date on the COA indicates when it went through setup and final QC in Pomona, CA.  It would be close to the date that the guitar shipped from Pomona.  On the newer COAs, Pomona leaves the date blank and it is filled in by the dealer.  I know this because the guitar I received on 08/12/2020 had the date filled in by Eastman/Pomona, and the guitar I received on 12/22/2020 had a somewhat different COA form, indicating the date was to be filled in by the dealer (since mine was drop shipped directly to me, the dealer never had the opportunity to fill in the date on the COA, and it is blank). 

Also based on these SNs, it could estimated that Eastman manufactured about 19,000 acoustic guitars (worldwide) last year.  Not only that, but production in the first half of the year was much lower than the second half.  For comparison, Taylor manufactured about 160,000 guitars in 2019 (reference https://www.insider.com/one-of-the-bigge...us-2019-10 ) 

That certainly demystifies the serial numbers. Thanks @cjhorne

Just for info, my E10SS (purchased September '21 from a dealer in the Netherlands as UK stock was sparse and the models I did see didn't quite cut it) has SN M2024645.

Looks like they got busy!

[cjhorne]

To add to this, I was looking at the Acoustic Shoppe website for the first time.  When you buy a guitar from them online, you pick out the exact instrument by SN.  They show photos and also the action measurements of low E and high e at the 1st and 12th fret.  I really like that!

The Acoustic Shop has a lot of Eastman guitars in stock (67 I think it was). I looked at the SNs of 20 of them.  Only one had a 2020 SN - SN 2021463.  The rest had 2021 SNs ranging from M2103140 to M2125102.

[Pura Vida]

I'm not sure we ever got the new numbering system verified by Eastman.  When they first went to the numbering system, we saw guitars with all sorts of different numbers, shipping right alongside each other.  So, in other words, I think the M20/M21 captures the year correctly, but the remaining number could still be random (or at least, not part of a sequential production number).  I recall one of the Eastman employees on the FB group confirming it was still fairly random for these new numbers.

But the old numbering system was a complete mystery.  A guitar with 1395xxxx could ship alongside of one with 1506xxxx or 1475xxxx, and they could all be the same model, year, etc.  At least we have the year with these new numbers.

[cjhorne]

We were well into 2021 before M21 serial numbers started showing up.  So it must take months from the time a guitar is serialized until it reaches the USA.

I doubt the SN system is completely random.  How would they assign SNs in such a system?  It would not make any sense.  What they might do is assign a bank of SNs to a certain product line, production line or building, depending on how they are organized. When that group of SNs is consumed, another group is assigned.  Photos of their shop don't show a lot of high tech equipment or computers.  Maybe they have them in the background somewhere.

Considering how long it takes guitars to reach the US, I still think the SNs may be assigned sequentially, but who knows?

If I were really ambitious, I would take all the models/SNs listed on the Acoustic Shoppe web page,  put them in a spreadsheet and look for a possible pattern.  They have about 60 Eastman guitars listed, and this would be a pretty good sample to work with.

CJ