Seiko Caliber 6r15d

Seiko Caliber 6R15

Seiko Caliber 6r15d

Manufacturer Seiko
Caliber Number 6R15 (A/B/C/D)
Movement Type Automatic
Diameter 27.40mm (outside), 27mm (casing)
Height 5.25mm
Jewels 23/24
Vibrations Per Hour
21,600 bph
Lift Angle
53 degrees
Shock System? Dia-shock
Mainspring Spron 510
Regulation
ETACHRON
Power Reserve
~50 hours
Winding Direction
Bi-directional
Hacking? Yes
Hand-Windable? Yes
Magnetic Resistance
4,800 A/m (60 gauss)
Functions Hours, minutes, central second hand, date at 3:00
Country of Manufacture Japan
Known Models
SARB033, Prospex Diver, SBDC053, SARB017, SPB047, SPB071, SPB083, SPB077, SPB079, SARX029, SPB049, SBDC033, SZSC004, SARX011 (Add yours in the comments below)

The Seiko caliber 6R15 is an automatic movement found in many modern Seiko dress watches and divers.

6R15/6R15A/6R15B/6R15C/6R15D

The general caliber number is 6R15, with 6R15A being the first version. The subsequent letter variations indicate evolution stages in the movements development. Early models of the 6R15 (A, B and some early C) were prone to issues that Seiko improved upon over the years. Because of the changes, not all parts are interchangeable between the variations. As of the time of this post, the latest stable version of this movement is the 6R15D (if this changes, please update the comments below).

Note: apparently some early versions of the 6R15C only have 23 jewels compared to the newer ones with 24J.

Base Caliber:

The caliber 6R15 is the base caliber for the 6R20, 6R21, and 6R24, and 6R27.

What are the differences?

All additional variations above have the power reserve indicator at 9:00 and a date subdial at 6:00. The difference is that the 6R20 and 6R21 have a day of the week subdial at 3:00. The 6R24 has a retrograde day of the week indicator at 3:00 (as well as a retrograde date indicator at 6:00. Which also explains why the 6R24 has 31 jewels instead of 29). The 6R27 has a power reserve indicator and date subdial. The 6R15 only has the hours, minutes, seconds, and date.

Other than complications, another difference between the base 6R15 and the variations is that the 6R15 beats at 21,600 and the other calibers beat at 28,800 with power reserve that drops from ~50 hours to ~45 hours. The jewel count on the 6R15 is 23, while the other calibers have increased jewel counts to accommodate the additional features.

6R15 vs NE15

The caliber 6R15 is basically a Seiko-only version of the NE15. Seiko Instruments (aka SII) sells the NE15 to other manufacturers (such as microbrands) for use in non-Seiko watches.

Accuracy:

Seiko claims an accuracy rating of -15/+25 seconds per day in normal temperature conditions (between 5 – 35 degrees C).

Seiko says this about accuracy:

  • The accuracy of mechanical watches may not fall within the specified range of time accuracy because of loss/gain changes due to the conditions of use, such as the length of time during which the watch is worn on the wrist, arm movement, whether the mainspring is wound up fully or not, etc.
  • The key components in mechanical watches are made of metals which expand or contract depending on temperatures due to metal properties. This exerts an effect on the accuracy of the watches. Mechanical watches tend to lose time at high temperatures while they tend to gain time at low temperatures.
  • In order to improve accuracy, it is important to regularly supply energy to the balance that controls the speed of the gears. The driving force of the mainspring that powers mechanical watches varies between when it is fully wound and immediately before it is unwound. As the mainspring unwinds, the force weakens.
  • Relatively steady accuracy can be obtained by wearing the watch on the wrist frequently for the self-winding type and winding up the mainspring fully everyday at a fixed time to move it regularly for the wind-up mechanical type.
  • When affected by external strong magnetism, a mechanical watch may loss/gain time temporarily. The parts of the watch may become magnetized depending on the extent of the effect. In such a case, consult the retailer from whom the watch was purchased since the watch requires repair, including demagnetizing.

Power Reserve:

The caliber 6R15 holds a power reserve of at least 50 hours. To fully wind the mainspring, turn the crown a minimum of 55 times.

Crown Position Functions:

0 (against the case): Clockwise = Manual Winding / Counterclockwise = Nothing
1 (pulled out one click): Clockwise = Nothing / Counterclockwise = Date setting
2 (pulled out two clicks): Time setting clockwise and counterclockwise

Stem Removal:

To remove the stem, make sure the crown is in position 0 or normal position (not date or time setting position). There is a lever with a small indentation for your tool. Gently press down while pulling the stem out. See official instructions below for more guidance:

Seiko Caliber 4r36 Stem Removal

Caliber 6R15 Drawings:

Seiko Caliber 6r15c Drawing

Video:

This video by Seiko examines the anatomy of the caliber 6R15D. The watch in the beginning is a Seiko Presage Karesansui model number SPB067.

Caliber Commentary:

From Monochrome Watches about the base caliber 6R15:

To say that the 6R15 is Seiko’s answer to the Swiss workhorse that is the ETA 2824 would be an understatement. Bottom line is that the 6R15 caliber is that GOOD a movement and with the sheer number of ETA-powered watches out there, it is sometimes nice to have something different to stir up the masses.

Seiko Caliber 6r15d Presage

Additional Resources:

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Seiko Alpinist SARB017: History & Model Review
4 years ago

[…] the power serve is raised up to 50 hours. But frequency numbers and caliber precision dropped. So, 6R15 is actually an improved version of 7S26. Seiko did a great job with it, but what enthusiasts would […]

Benson Go
Benson Go
4 years ago

#SARW021 (6R21)
#SBDC065 (6R15)
#SBEJ003 (6R64)

johnnyjohnny
johnnyjohnny
4 years ago

kind of odd that i’d get a notice about this movement since i never commented or posted on this movement’s thread, but i DiD purchase a new seiko baby marine master SBDC061 and received it yesterday. kind of some paranormal activity going on. but since i got this link for no reason in my email but did get the baby marine master with the 6r15 movement in it, and i set it about 36 hours ago i will state right now it is about 1/2 second down after 36 hours. that’s way beyond COSC standards. again, i’m only posting because… Read more »

johnnyjohnny
johnnyjohnny
4 years ago
Reply to  calibercorner

well, to be quite honest, i believe in paranormal phenomenon and have had quite a bit of it my entire life…i may have checked out the 6r15 page of yours, but do not recall having done so, and don’t at all recall having subscribed to it. i think you have a great website and check your posts on seiko movements i had already owned, the 7s26 and NH35. google only shows my visiting this page today, which would have been earlier after receiving your email notification. if you can find some other explanation other than the metaphysical for this notification,… Read more »

johnnyjohnny
johnnyjohnny
4 years ago
Reply to  calibercorner

just checked my subscriptions to your website, did NOT include this movement. only had two, one was for the NH35 and the other for an eta caliber. happy Halloween ;D

Manny Brown
Manny Brown
4 years ago
Reply to  johnnyjohnny

I have the same watch too (baby mm200). It keeps excellent time. Please update us on your watch. My watch is at 20 days with -0.7 secs/day.

Ed
Ed
4 years ago

Sarb027, Sarb029, Sarb30, and Sarb031 also sport this movement.

Daniel Burdiek
Daniel Burdiek
4 years ago

After a little playing around, I managed to get my 6R15D to an impressive -4 seconds a day.

Pam
Pam
2 years ago
Reply to  Daniel Burdiek

How did you do this yourself can I ask? I want to try.

Michael Major
Michael Major
10 months ago
Reply to  Daniel Burdiek

6R15D here, as well. I’m seeing +/- 1 sec/day as a matter of routine. Took a while to get it adjusted to that level of accuracy, and if I change use for a day or two, it wanders off. But if I wear it 24/7, it holds onto the correct time stubbornly.

Scott
Scott
4 years ago

The 6R15 goes in more expensive watches than the 4R35, but I can’t find a description of how exactly the two movements are different. (Other than the power reserve, which doesn’t really matter to me as long as it keeps running overnight.) More accurate? Doesn’t seem so. Better materials? Longer life? Even Seiko doesn’t seem to describe what’s special about the 6R15. This year, Seiko is dropping the less expensive models that have the 6R15, like SARB033 and the Alpinist, putting the 4R35 in models that cost up to $600 and moving the 6R15 to $700 and up. I have… Read more »

D
D
3 years ago
Reply to  Scott

Three differences are, Finishing, SPRON 510 mainspring, SPRON 610 hairspring.

Alvin C
Alvin C
4 years ago

The 6R64 GMT movement (SBEJ001, SBEJ003) appears to be a further development of the 6R27 (the power reserve and date subdial are in the same positions relative to the crown).

Chad
Chad
4 years ago

The SARX055 also has a 6R15D

trackback
New Watch Alert 2.28.20 - The Truth About WatchesThe Truth About Watches
4 years ago

[…] with manual winding capacity.” And no wonder. It’s Seiko’s mid-market Calibre 6R35, with a claimed +25 to -15 seconds per day accuracy. Hardly the kind of thing you’d use for […]

Jesse
Jesse
3 years ago

I have a SARB045 And it has a 6R15B . I gotten +2 / -3 And Thats COC numbers. I can see why Some Seiko enthusiast call it the “ Baby Grand Seiko . Ohh yeeeah

trackback
Seiko Alpinist SARB017 Quick Review - Relozo
3 years ago

[…] The Alpinist houses an 6R15. This is an upgraded version of the 7S26 with hand-winding and hacking. This is the same movement used in the SARB033. Seiko advertises the movement as having an accuracy of -15/+25, but this is mostly because it’s giving itself some leeway. Some people have reported better accuracy and I can vouch for that. For the duration I have owned this, I can report a +4 to +5 s/d on a full wind. You can find more information about the 6R15 in the caliber corner website. […]

Mark
Mark
3 years ago

The 6R15 in my Alpinist is actually more accurate that the 3132 in my Rolex Explorer, -1 second per day against +2.5 in a watch that was 10% of the price.

TjieJoeng
TjieJoeng
3 years ago

The Brightz collection SDGM001 etcetra. (“baby GRAND cocktail”). One of the undervalued & underexposed models in SEIKO’s collection(s). Price Quality ratio TOP comparing to Swiss “CLONES”:)

Pandra
Pandra
3 years ago

SDGM003 (6R15C)

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Atelier Wen Porcelain Odyssey Ji – Beans & Bezels
3 years ago

[…] SPB047 has an enamel dial and can be found under $1000, but has a rather uninspired design and a 6R15 movement, which in my opinion, is a bit underwhelming for a $1000 watch. anOrdain makes a great […]

trackback
Atelier Wen Porcelain Odyssey Ji – SaFonaGastroCrono
3 years ago

[…] SPB047 has an enamel dial and can be found under $1000, but has a rather uninspired design and a 6R15 movement, which in my opinion, is a bit underwhelming for a $1000 watch. anOrdain makes a great […]

trackback
20 Best Automatic Watches Under $500 | Watch Researcher
3 years ago

[…] on this list of the best automatic watches under $500. The classic model of Seiko SARB035 runs on a premium 6R15 automatic caliber with hacking and manual winding capability, while holding a power reserve up to 50 […]

trackback
SEIKO Monster: Las Cuatro Generaciones – SaFonaGastroCrono
3 years ago

[…] más discreta. La tercera generación también empleó un calibre notablemente mejorado, el 6R15, pero perdió con ello la función del día. Finalmente, el cristal añadió un magnificador sobre […]

trackback
Seiko Presage Shippo Enamel SPB075J1 Review - FIFTH WRIST
3 years ago

[…] the Seiko Presage Shippo is, it has one major flaw – it only comes with the rather pedestrian 6R15 movement. If it came as standard with something packing just a little bit more of a punch, then this would […]

trackback
SEIKO Presage Cocktail Time Blue Moon: El De La Boda. - SaFonaGastroCrono
2 years ago

[…] de color negro y un cierre de mariposa con el logo de la marca grabado. Equipaba el conocido calibre 6R15, un movimiento de la gama media de SEIKO, que late a 21.600 alternancias (3 Hz), con posibilidad de […]

Ryan
Ryan
2 years ago

Watch movements are simply fascinating

Cantino
Cantino
2 years ago

Hi, my SPB087J1 gets around -19 sec per day after two years of wearing it every day. quite disappointing imo! How can you improve this accuracy?

craig watanabe
craig watanabe
2 years ago
Reply to  Cantino

Perhaps you are not moving enough during the day? 1-Try a full wind (40-50revs). 2-Rolex has recommended “dial up” to speed up, “crown down” to slow a bit, “crown up” to slow more, when watch is taken off. 3-Remove the caseback and adjust the regulator. Was the slowing gradual? Two years is quite soon for a new Cal 6R15 to require service. As stated above, Seiko claims an accuracy rating of -15/+25 seconds per day but most have much better results. What have you tried?

keepthetime
Admin
2 years ago
Steve
Steve
2 years ago

SARB065 original JDM version of the “Cocktail Time” housing a 6R15C, purchased new July 2017.

Steve
Steve
2 years ago
Reply to  Steve

My above referenced SARB065 with 6R15C was manufactured October 2016 according to the S/N.

trackback
SEIKO Sumo: El Olvidado - SaFonaGastroCrono
2 years ago

[…] reloj era una pieza un tanto especial, ya que montaba el (ahora ya extendido) calibre 6R15, un calibre de gama media que montaban pocos relojes de SEIKO y que se circunscribía sólo a […]

sam
sam
2 years ago

Is possible to swap 6r15 to 6r2x for a higher bph?

watchhans
watchhans
2 years ago
Reply to  sam

The 6R2x-movements are thicker. They won’t fit in a 6R15-watch case.

trackback
Seiko Alpinist SPB089 Limited Edition – Beans & Bezels
2 years ago

[…] watch uses Seiko’s 6R15 movement, which is a tier above their 4RXX and NH3X series. At $600, I think this is pretty good […]

denztamz
denztamz
2 years ago

SARX035, SARX033

Bill
Bill
2 years ago

I have the SARB 033 with 6R 15-D 23 jewels and it’s “Extremely Accurate” +2 sec daily! Fortunately I bought it as they were being discontinued for $389! Great watch!!

SeikoTurkey
SeikoTurkey
2 years ago

my black sumo SBDC001 also have the same calibre

trackback
Seiko Monster modelos | Distribuidor oficial | Maresmajoiers.com
2 years ago

[…] empezó a ver la luz sobre el año 2014, también empleó un calibre notablemente mejorado, el 6R15, pero perdió con ello la función del […]

trackback
Owner Review: Seiko SARB035 - Discontinued, but not Discontent
1 year ago

[…] second hand. Under the hood, and visible through the exhibition case back is Seiko’s esteemed 6R15 movement. It isn’t beautifully decorated, but it hacks, hand winds, and is reliable. Seiko even signed […]

trackback
SEIKO SZSC005 “Jade Monster” - SaFonaGastroCrono
1 year ago

[…] queda citar el calibre que lleva la tercera generación, que es el 6R15. De hecho, no ha habido cambio generacional sin cambio de calibre (el 7S26 en la primera, el 4R36 […]

Clontsy
Clontsy
1 year ago

I bought my Sumo from Seya (spelling?) Japan in 2013. For years I’d had regulation issues with the 6r15. I even sent it out for repairs at over $200.00. I tried to adjust it myself, but could never get the seconds per day anywhere close to 0. I was about to throw it into the back of my closet and forget about it, but finally thought that I would just get a new movement which was the 6r15 equal – NH15. My friend, tinkers with timepieces gladly removed the 6r15 and replaced it with the NH15. Since then, I am… Read more »

Tim Ashton
Tim Ashton
1 year ago

Been on my wrist now for a little over 5 weeks. Cannot believe that for au$240 I have a watchthat is -2 secs per day.

M. McMurphy
M. McMurphy
1 year ago

You have the most comprehensive information on the 6R15 movement I’ve come across, and for that I’m grateful. My Seiko SBDC007 Titanium dive watch that I bought new from Japan in 2015 also has this movement. Cheers…

Jack Easley
Jack Easley
7 months ago

wonderful videography

Anthony
Anthony
6 months ago

SARX023 – purchased 2015 – 6R15C 23 jewels

Daniel Kashani
Daniel Kashani
6 months ago

My SPB047 enamel has the 6R15(D) movement.

Alireza
Alireza
2 months ago

#SARX057

Seagull Caliber St19

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