Seiko TMI SII caliber PC21S movement

Hattori SII Caliber PC21S

Seiko TMI SII caliber PC21S movement

ManufacturerHattori aka Seiko Instruments Inc. (SII)
Caliber NumberPC21S
TypeQuartz, battery-powered
Diameter18.5mm
Height
3.15mm thick (overall height 4.8mm)
Jewels0
Frequency32,768 Hz
Battery Cell NumberSR626SW
Estimated Battery Life
2 years
Quartz TypeTuning fork type quartz crystal
Stem354222 / tap 10
Hands Count
3
Hand Sizes1.20 / .70 / .17mm
FunctionsCentral hours; central minutes; central seconds
Country of ManufactureMade in Singapore
Known Models Many cheap quartz watches from China (Add your watch to the comments below…)

Seiko Instruments caliber PC21S is a 0 jewels quartz movement found in many ultra-entry level timepieces. This 3-hander caliber is a true no-date movement.

Note: This caliber number is often misread as “PC215”.

Manufacturer Labeling:

You might find this caliber listed as being produced by Hattori aka Epson aka TMI (Time Module Inc) aka Seiko Instruments Inc. Learn more about this here.

Country of Origin Labeling:

You also may see sellers listing this as a “Japan” movement or “made in Japan”, despite the movement actually being signed “Singapore”.

Accuracy Rating:

Official claims from Time Module, Inc. states an accuracy of “less than 30 seconds per month at normal temperature range,” aka +/- 30 seconds/month.

Replacement Prices:

Replacement prices for the calibre PC21S were found in the range of $2.00 to $7.95 USD at the time of this post.

Drawing:

Additional Resources:

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Keep comments respectful and on the topic of Hattori SII Caliber PC21S. For off-topic or general watch questions, post in the member's forum.

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20 dollars or less, let's see them! - Page 408
6 years ago

[…] took the photo sharp enough to zoom in: (still hardly readable) It's a PC21S, made in Singapore, according to this site (first hit in google…don't know how dependable the info is), it leads back to Seiko. […]

tigbwat
tigbwat
6 years ago

And by “Most cheap quartz watches from China” you do mean fake watches right?

LewisB314
LewisB314
6 years ago
Reply to  tigbwat

Fake only if they try to sell it as something it isn’t. I’ve bought a few that were very open about Made In China, shipped from China. Nothing fake about it, it was a Chinese watch.

Notyourgrandad'swatch
Notyourgrandad'swatch
2 years ago
Reply to  tigbwat

Why does everyone assume Chinese watxhes are all fakes? China makes some of the most reliable movements on the market. They have a very long history of producing watches only just recently having a bad rap because alot of counterfeit watches come from there. Fake isn’t a term usually used anymore. China also produces some of the best homage watches at affordable prices. Now if people want to argue that homage watches are rip off or counterfeit they aren’t. They have earned thier place in the market and have alot of respect among true collectors. Technically most watches are homages… Read more »

Ian Watson
Ian Watson
1 year ago

I’m currently tackling a fake Rolex, actually its a fake of a real thing churned out after work hours by employees of the real thing but I digress… the Molnija 360x is a 1940’s Rolex movement that went on to become possibly one of the most produced mechanical movement vying for the top spot with Vostok’s 24xx range and the Swiss EB8800’s. It was also one of the rare occasions the Soviet’s didn’t steal the movement and like buying that complete watch factory from America, the Soviet’s bought the whole production line to give them a decent pocket watch movement… Read more »

Todd
Todd
5 years ago

Thank you for the info on this, I saw this movement in the Curren model 8266 and I had wondered who the manufacturer was. Excellent quality for the cost of this budget timepiece! Even though it is one of Seiko’s cheaper movements, the quality is still going to be much better than a lot of the other Chinese quartz movements that use plastic gears.

Herb
Herb
4 years ago
Reply to  Todd

This has plastic gears too. You can see in the pictures.

Eustachy
Eustachy
5 years ago

One of the names of these cheap Chinese quartz watches was TWINS. After 20 years, mine is still quite pecise though, about 2 seconds per week.

Olivia Gabriela Ruginosu
Olivia Gabriela Ruginosu
5 years ago

Of mine is write Gucci quartz , is very old and has the same thing on the back like this one . So it’s fake yeah ?

Jerry's Watch Frenzy
Jerry's Watch Frenzy
5 years ago

I don’t know but probably. This mechanism is used in many fakes.

Herb
Herb
4 years ago

Gucci would never use this movement. Gucci is a luxury brand whose watches cost thousands. This mostly plastic movement is one of the cheapest in the world.

Zachmonoda
Member
2 months ago

It may well be very real Gucci, and likely is! Gucci is a fashion company with one goal only: Sell dirt cheap stuff to people with a huge ego and delusions of grandor for a lot of money. Markups in the fashion “industry” are insane. There is a reason, why you can buy last season’s fashion overstock at Ross for less than 1/10th of retail, and they still make profits. Gucci is not a watch company, but a fashion design company, and they do not give a rat’s tail about what is inside. The PC21 is a rock solid, fine,… Read more »

Daimon
Daimon
4 years ago

Tengo uno Montreal Carlo q dice en la tapa Japón eso es bueno?

Carolyn
Carolyn
4 years ago

I’ve installed a new battery in this movement but the watch still won’t run. Does anyone know why?

Herb
Herb
4 years ago
Reply to  Carolyn

The battery could be bad, maybe you shorted it while installing it. Is it possible the movement wasn’t working to begin with and you just thought it was the battery?

Herb
Herb
4 years ago

What I love about movements like this is that they are so cheap you just replace the entire thing. Nothing to fix, nothing to worry about, just pop a new one in if you know what you’re doing. It’s quartz so it works just as good as any other quartz would.

John E
John E
4 years ago
Reply to  Herb

Replacing the movement involves removing and reinstalling the hands.
Have fun with the second hand.

Nplus1 Watches
Nplus1 Watches
4 years ago

I bought a Daiso Rosso Bianco watch for 500 yen (less than $5) a couple years ago and it’s amazing to me how accurate this movement is. I set it couple months ago to atomic time, and right now it’s only 5 sec slow. It’s the most accurate, yet cheapest, watch I have in my collection of quartz and mechanical watches.

Ludwig
Ludwig
4 years ago
Reply to  Nplus1 Watches

Yes! I bought also last year a daisy watch, called antique watch. The same movement is inside. On the package they have written: With a movement made by a Japanese company, manufactured in singapore. And it is a Sii Seiko movement! Very accurate! I have bought three watches more…

Peter
Peter
4 years ago

I’ve found an identical movement in another Gucci fake. The only cosmetic difference is the manufacturer’s marks.
The top line in the above pic … S11 O PC 21S, is replaced by TIME MODULE INC. PC 21AA, and their initials TMI in logo form then appear between the two lines over to the far left i.e. positioned between the postions occupied by S11 and SING.. in the original pic. Finally the bottom line SINGAPORE is replaced by JAPAN.

Peter
Peter
4 years ago
Reply to  Peter

Apologies I missed a typo in the above … please read PC 21A for PC 21AA

MCompeau
Member
3 years ago

Used in Rocawear ref RM0106 chronograph styling with faux subdials and pushers. Top shelf. 🙂

MCompeau
Member
3 years ago
Reply to  Mike Compeau

Oh, and FWIW – accurate to within 0.2 seconds per day over a 9 day period…so… I punt. I have a Tissot that doesn’t keep time that well.

DH_3_5
DH_3_5
3 years ago

Bought an $8.00 watch, the Walmart George brand because I needed a watch band for a watch, until its replacement arrived in the mail. Buying the whole watch for the band was cheaper then buying a new cheap temporary band only. Anyway, the watch has the PC21J Seiko movement so I think Ill use it as an aid to learn how to use different watch repair tool, and its a field watch style, so I’ll see what I can come up with and maybe using some old Seiko’s I bought at the flea market for two bucks apiece. any ideas… Read more »

Wibowo PR
Wibowo PR
2 years ago

if Citizen has Miyota, then Seiko has TMI

TMI (Time Module) is a trademark for the sale of watch movements made by Seiko Instrument Inc (SII) in Japan and Seiko Manufacturing outside Japan

and unexpectedly, it turns out that TMI is also playing in the disposable movement market like Sunon and the like

K3ORS
K3ORS
2 years ago

I was given a Michael Kors Chronometer that didn’t run. New battery didn’t work. Upon removal of movement I couldn’t see how the other dials worked. Duh, they don’t because that isn’t what the movement does. “Curses, foiled again.” Shame as it’s a pretty watch.

Notyourgrandad'swatch
Notyourgrandad'swatch
2 years ago

China has really leaned into being proud of thier heritage amd branding on thier watches. One of the best and most respected companies to look into is Seagull. They make some incredible watches, with some of thier higher end movements rivaling Swiss movements. Swiss movements is up for much interpretation as of late with updates to the definition as to what makes a movement Swiss. Less and less parts are being produced in Switzerland that are going into these more expensive watches.

William Millsaps
William Millsaps
2 years ago

I love Seiko watches I own 6 at this time.
I just want to thank you for making such perfect timepieces. I’m saving for a second Grande Seiko. You have a loyal
Customer and Fan. Thanks again

trackback
SII/TMI Caliber PC21J Watch Movement | Caliber Corner
2 years ago

[…] is a similar caliber PC21S with the main difference being that the PC21J discussed on this page has a longer battery life of 3 […]

Daniel
Daniel
2 years ago

I came across a Movado watch,replaced the battery only to find out it had a TMI Pc2o replacement inside…bummer. The watch looks authentic but I still have questions about it.No stamps on the clasp and stainless steel band is tarnished.

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20221022_210615.jpg
richard
richard
1 year ago

They are also sitting in this kind of fashion watches,sII pc 21,looks very anatomic to me ,the building of a pc 21.

16744802481094228649112251282712.jpg
Ian Watson
Ian Watson
1 year ago

We will see less and less of the Sii model as Chinese in house quartz movements like the SL-28 are fast becoming the norm. The SL28 was designed to fit in Seiko sub brand models like Lorus etc so expect to find it inside more higher end stuff like a Seiko SQ I bought a few years back and had one of these cheeky beggars sitting inside.

Drockmd
Drockmd
1 year ago
Reply to  Ian Watson

Whats a good mechanical movement to swap out for a SL-28

Drockmd
Drockmd
1 year ago
Reply to  Drockmd

I tried the NH-35A but the date wheel is a little to big for the face. (As in its not centered in the face date window)

CJDUDHF
Member
7 months ago
Reply to  Ian Watson

SL28 is not repairable just like Seiko PC series

Seagull Caliber St19

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