Valerii Danevych caliber W00D-1
Seiko Caliber 6r35

Seiko Caliber 6R35

Seiko Caliber 6r35a

ManufacturerSeiko
Caliber Number6R35, 6R35A
Movement TypeAutomatic
Diameter27.40mm (needs confirmed)
Casing Diameter
27mm (needs confirmed)
Height5.25mm (needs confirmed)
Jewels24
Vibrations Per Hour
21,600 bph
Lift Angle
53 degrees
Shock System?Diashock
MainspringSpron 510 (needs confirmed)
Regulation
ETACHRON
Power Reserve
~70 hours
Rotor Direction
Bi-directional (Magic Lever)
Hacking?Yes
Hand-Windable?Yes
Magnetic Resistance
4,800 A/m (60 gauss)
FunctionsHours, minutes, central second hand, date at 3:00
Country of ManufactureJapan
Known Models
Presage models: SPB127, SPB131, SPB129, SPB115, SBP113, SPB095 (Arita), SPB111 / Prospex Alpinist: SPB117 (SBDC087), SPB119 (SBDC089), SPB121 (SBDC091), SPB123 (SBDC093) / Prospex “Sumo”: SPB101, SPB103, SPB125 (Add more in the comments below)

The Seiko caliber 6R35 is an automatic movement that is part of what Seiko refers to as the high performance 6R series caliber. The 6R35 is considered an upgrade from the caliber 6R15. Watches with the 6R35, such as the Presage Arita Porcelain were announced at Baselworld 2019. The Prospex SPB149 powered by the 6R35 was announced in March 2020.

6R15 VS 6R35:

The caliber 6R35 is beginning to find its way into watches that used to house the 6R15. The biggest difference between the two movements is a 20 hour increase in power reserve. The 6R15 has a power reserve of approximately 50 hours and the 6R35 has a power reserve of approximately 70 hours.

6R35 / 6R35A / 6R35B / 6R35C:

This is still a rather new movement, so currently there is only the 6R35A. The general caliber number is 6R35, with 6R35A being the first version. The subsequent letter variations indicate evolution stages in the movements development. This post will be updated if the movement gets any upgrades.

Accuracy of the 6R35:

Seiko claims the accuracy of the caliber 6R35 has a 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 6R35 holds a power reserve of at least 70 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

Can you overwind the movement?

No. According to the Seiko documentation, manually winding the movement after it is already fully wound will not break the spring.

When can you adjust the date?

Do not adjust the date between 9:00 PM and 1:00 AM.

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

How often does the 6R35 need serviced?

According to official Seiko documentation, watches with the caliber 6R35 should be serviced every 2-3 years. Learn all about Seiko service intervals here. At the time of this post, the starting cost of getting this movement overhauled by Seiko is $260.00 USD.

Examples of watches with caliber 6R35:

Additional Resources:

  • Seiko 6R35 official instruction manual here
You are reading Caliber Corner, the most popular resource for watch movement pics, specs, mods and DIY repairs. Follow @calibercorner on Twitter, Instagram and Facebook. Subscribe to the YouTube channel. Join our mission to spread movement awareness. Sign up!
What do you think about Seiko Caliber 6R35? Keep comments respectful and follow our community guidelines.
Subscribe
Notify of
guest
66 Comments
oldest
newest most voted
Inline Feedbacks
View all comments
Jyrgen N
Jyrgen N
10 months ago

The 6R35 is also in the SPB113J1 (Presage with white enamel dial) I bought two weeks ago. So far I have observed deviations from +3 to -3 s per day; the day I saw the latter may have been one with very little activity. So far I am as happy with the caliber as with the watch in general, meaning *very* happy.

Jyrgen N
Jyrgen N
9 months ago
Reply to  Jyrgen N

The above was during a time when I had relatively little activity during staycation. In between I have seen that in a normal work week the clock gains about 20 seconds, meaning around +3 seconds per day on average. Good!

Don Jones
Don Jones
9 months ago

It’s also in the new SPB151 & SPB153 models

Bryan W
Bryan W
8 months ago

Also in the SBDC101/SPB143 series MAS62 reissue watches.

Gareth Davies
Gareth Davies
7 months ago

With regard to my SPB143J1, I am getting +15 seconds a day. Quite disappointed really.

zeke
zeke
6 months ago
Reply to  Gareth Davies

that will slow down over a month run in time…i have spb149 and for the first few days it was +1 a day now afther 3 weeks of 24/7 wear its now -10 per day

Gareth Davies
Gareth Davies
6 months ago
Reply to  zeke

Alas, after two weeks my watch was gaining up to 28 secs a day. Spoke directly to Seiko, who asked me to return the watch for adjustment and have subsequently written to me explaining they will rectify any defects, but it will take at least 3 weeks to test the watch properly. Will keep you posted as how the watch performs once returned to me.

Gareth Davies
Gareth Davies
6 months ago
Reply to  Gareth Davies

Received my watch back from Seiko after 4 weeks. They have replaced the entire movement, all under warranty. It’s currently gaining gaining plus 9 secs a day, but hopefully it will bed in and improve. Fingers crossed

Simon
Simon
1 month ago
Reply to  Gareth Davies

But a demagnetiser from eBay for £6. 9 times out of 10 that will sort it. Do you ever have your watch near your mobile?

JY
JY
4 months ago
Reply to  Gareth Davies

I have the SPB147 and find it running fast around +30/day wearing it daily for the week. It’s a new piece so I’m hoping for better results as it goes along. Disappointed so far though. I might need to call Seiko.

Simon
Simon
1 month ago
Reply to  Gareth Davies

I have a couple of Grand Seiko hi beats and a spring drive. I have just got a presage Alpinist (which has the 6R35a). It’s only 5 secs slow after four days of wearing. Try not taking yours off. If it’s running fast it may need de-magnetising. Or it’s you. Not much you can do about that. Anyway. That movement should be performing better than you are getting.

Eric O.
Eric O.
1 hour ago
Reply to  Gareth Davies

I don’t understand being disappointed with +15 seconds per day when the 6R is rated as -15/+25 seconds per day by Seiko. Why do people expect COSC performance with watches that are advertised with a range of 40 seconds.

trackback
Reseña SEIKO SPB143 – SaFonaGastroCrono
6 months ago

[…] finalizar hablaré de su calibre, el movimiento automático 6R35, la evolución del 6R15. Ha aumentado su reserva de marcha hasta las 70 horas y su latido es de […]

Benjamin Kingsmill
Benjamin Kingsmill
6 months ago

It gains too much time in a day! I’m constantly readjusting it, wish it was a quartz! So disappointed for an £740 watch!

Benjamin Kingsmill
Benjamin Kingsmill
6 months ago
Reply to  Caliber Corner

Hi, yes I checked to see if my seiko sumo 3rd gen was magnetised with this ‘Lepsi’ app you can download, and it was showing that it is not at all. My watch is only a few months old, I have wound it up fully and then let it unwind all the way down ( which was recommended on another watch site) and then wound it back up and worn it for 3 weeks, it… Read more »

Gareth Davies
Gareth Davies
6 months ago

Ben, if you are in the UK. Speak to Beverly in Seiko customers services. Explain your situation and return the watch to them. If the movement needs changing, they will. She’s very understanding and obliging. Your watch comes with a warranty for a reason. The 6R35 is not bullet proof. I know that and so do Seiko.

Benjamin Kingsmill
Benjamin Kingsmill
6 months ago
Reply to  Gareth Davies

Ahh thanks so much Gareth! Really appreciate this thread and website forum, and speedy assistance!.. I have just wound my watch up again and set it to the speaking clock and I will monitor carefully for a week just so I have definitely got my facts straight and then if still the same, and I see no reason why it won’t be!, I will send it in, from your advice! All the best , and… Read more »

Myles
Myles
5 months ago

Hi, Ben.

Does the Lepsi app require you to place your watch in close proximity to your phone? If so, that’s an excellent way to *magnetize* a watch movement! Instead, use a small compass, or better yet, buy a cheap demagnetizer and treat the watch empirically with the demagnetizer. It can’t hurt.

Good luck!

Myles

Bari W
Bari W
6 months ago

JUNK. Absolutely junk of a movement. Bought my SBDC101 (aka SPB143) with this 6r35 movement, and the quickset date no longer works… Extremely disappointed in Seiko. Luckily I have warranty, so I will get this watch fixed. I bet they will charge me to ship it over to Japan too. As soon as I get this watch fixed I am going to sell it off… doubt I will ever try another Seiko again. It’s a… Read more »

Laurens vH
Laurens vH
5 months ago
Reply to  Bari W

Dear Bari, I can imagine you are disappointed, but your are now basing your evaluation of the Seiko brand off one bad experience. If I did the same I couldn’t buy any Rolex (misaligned bezel on a GMT Master) or Omega (1 minute a day fast on a Speedmaster) or any watch from any brand for that matter. Sometimes bad ones slip through QC, and sometimes stuff breaks… Seiko’s are (very) good watches and offer… Read more »

Simon
Simon
1 month ago
Reply to  Laurens vH

Completely agree. Seiko are excellent watches. And produce models for all situations. But they are still – despite a shift in the market it’s chasing – mass produced.

If you want better or far more reliable you have to pay for it.

Simon
Simon
1 month ago
Reply to  Bari W

Don’t blame you for being angry. That’s just not right. Unless you have left the watch near a magnetic source. That moment is not good enough for a £1,000 watch but should not be that crap. That said I have several Seiko watches with the 6R35A and none of them perform as poorly as yours. If you want a decent movement I suggest you buy a grand seiko and leave the mass market models to… Read more »

Mike T
Mike T
5 months ago

The book says 20 winds to get it going and no damage done if you over wind. Saw a comment saying 50 winds to max its out. How many winds to do….

Max
Max
5 months ago

Just got an SPB149J1 second hand with blank warranty card. Really liked the look of it and splurged for my first seiko. (too bad it was sold out everywhere pretty fast) Running +45 seconds per day :-(. Will seiko honor their warranty on it or with a blank card I am stuck. Also the bezel feels weird as after the click it still has a bit of play. Is it normal? Has anyone experienced this?… Read more »

Simon
Simon
1 month ago
Reply to  Max

Just to be clear – as a regular contributor to watch magazines and websites etc – the 6R35A does not have a silicon mainspring. It is made of metal. I guarantee in almost all cases that if your watch with that movement is running fast it’s because you let it get too close to your mobile or radio or some electromag source (of which modern homes are crammed). But a £6 demagnetiser from eBay and… Read more »

Marvin
Marvin
5 months ago

Does Seiko have a 6R movement with no date/open heart? I know about the 4R71 and the 4R38 but was hoping they have something in the 6R range that has a 70 hour PR. I wish Seiko released more time only watches. Their new bezel-less Alpinists (SPB155J, SPB157J, SPB159J) will look great as time-only pieces. Part of me is daydreaming of SPB156J, SPB158J, SPB160J as references for those.

Chris
Chris
5 months ago

I had an issue with the new Alpiniste, the time gain was large and inconsistant, anything from 10s to 60s in a day! The watch was replaced under warranty and the new one is great, less than a minute gained over a week.

Jay J
Jay J
4 months ago

I just got the new SPB153 Captain Willard with the 6r35 movement. Is it normal for the seconds hand to pull back slightly when you set the time counter clockwise? I have 2 3 other Seiko and don’t do that.

Simon
Simon
1 month ago
Reply to  Jay J

Yes. Live with it

Stefan
Stefan
1 hour ago
Reply to  Simon

My Rolex did that too!

Jack Daniel
Jack Daniel
4 months ago

I have a 4r15 I’ve had it on a watch winder for a month while I was on away. On average it gained about 4 seconds a day.

Roman garcia
Roman garcia
3 months ago

Hola yo tengo el nuevo sumo verde y la verdad que se tuvo que llevar a servicio pues el remonte manual no funcionaba lo lleve unos días y me daba un promedio de más 3 segundos día aún dejándolo pon la noche en reposo después de arreglarlo me está dando más 6s el tema es que esos seis segundos me los coje de noche cuando me lo quito o aveces duermo con el . No… Read more »

Roman garcia
Roman garcia
3 months ago

No se si fue de llevarlo a servicio pero me uviese gustado que saliera con sus más 3s de todas maneras se está diciendo en muchos foros que el calibre está dando muchos problemas de diferentes campos haqui en españa cuesta 900euros unos 1000 dorares por ese precio hoy por hoy hubiese comprado longines hizroconques por 70euros mas

MARK WOLFSON
MARK WOLFSON
3 months ago

Wow, now wondering whether I want to touch this calibre…Was seriously looking at the SPB153J1. I will go back to Yema instead.

Olivirer REINACH
Olivirer REINACH
3 months ago
Reply to  MARK WOLFSON

All brands have their issues! on the Yema superman heritage 63 it seems that there is a lot of problem with the crown which, when unscrewed, wanders and the locked bezel inoperative

MARK WOLFSON
MARK WOLFSON
3 months ago

I agree with you for sure! Maybe we should all protest by buying G-shocks! LOL Have a Happy Thanksgiving.

Olivier
Olivier
3 months ago
Reply to  MARK WOLFSON

I squinted too at the Yema superman 63 but I really think that for a watch of this price the movement is not terrible (Selitta) and the finish seems shabby with in addition unpleasant after sale service experience! So to please myself I turned on  to an Islander # 53.I gess I get it for Noël (en France!) Marc is an enthusiast who never lets out a shame watch. I already have an Islander SKX013,… Read more »

MARK WOLFSON
MARK WOLFSON
3 months ago
Reply to  Olivier

Marc is a real enthusiast, would like to see close up one of his watches. Are you satisfied with the finish? Also, what do you think of the new Seiko SPD153J1?

Olivier
Olivier
3 months ago
Reply to  MARK WOLFSON

First of all I would like to apologize for my rusty English and Google help!   As for the finish of my upgraded SKX013 which comes from Marc I find it very good: perfect polishing, including between the lugs, bezel well aligned with the chapter, day / date well aligned with the Islander dial window and the sapphire crystal is perfectly centered on the ceramic bezel insert; everything is beautiful ! and it lasts +… Read more »

Olivier
Olivier
3 months ago
Reply to  Olivier

Just another thing : the rotation of the bezel is generally quite hard on Seiko

MARK WOLFSON
MARK WOLFSON
3 months ago
Reply to  Olivier

Thank you!

trackback
Seiko Caliber 6R35A Watch Movement | Caliber Corner
3 months ago

[…] 6R35A (6R35) […]

trackback
Presentación SEIKO Alpinist SPB199J1 – SaFonaGastroCrono
3 months ago

[…] crema y la SPB121 verde oscuro. Estas referencias se presentaron con un calibre mejorado, el 6R35 automático con una reserva de marcha de 70 horas (frente a las 50 horas de la generación […]

Peter Laurence-couzens
Peter Laurence-couzens
2 months ago

I’ve had a spb155j1 for around a month now, and the accuracy seems to be plus 1.45 seconds a day. I set it to my iPhone clock when I got it and have worn it every day since, but have not adjusted the time. Really pleased with the timekeeping. I do have a question though. Does anyone know for certain if the 6r35a has a quick change date, or not? Currently the date starts to… Read more »

MRQ56
MRQ56
2 months ago

I’m thinking you mean quickset date? This usually means the date can be quickly set with the crown in a date setting position. Older watches can’t be set so quickly and you have to go all the way around with the hands. The 6R35a is quickset. I think it’s normal if the date starts to change around 11. Someone else can comment, but most of my watches do the date change between 11pm and 1am.… Read more »

Peter Laurence-couzens
Peter Laurence-couzens
2 months ago
Reply to  MRQ56

Thank you for your reply. No, I meant quick change, not quick set. Yes mine seems to take some time to change. All my other watches change over quickly at midnight, (or very near). If as you say the 6r35 takes a couple of hours then it would seem that my movement is behaving normally.
Thanks again for your reply.

MRQ56
MRQ56
2 months ago

Well now I need to check mine to make sure I am not giving you the wrong information. I thought mostly watches like Rolex were really fast date changers. I will check my Seiko tonight at midnight!

Peter Laurence-couzens
Peter Laurence-couzens
2 months ago
Reply to  MRQ56

I can only speak for my meagre collection, namely a mondaine (day/date) clicks over at midnight, seiko solar chronograph clicks over at midnight, rado captain cook clicks over at midnight, rotary quartz clicks over at midnight, citizen quartz chronograph clicks over at midnight, and a guess quartz dress watch clicks over at midnight. Others don’t have dates. So, the only one that changes over a period of a couple of hours is my new seiko… Read more »

Random Randy
Random Randy
2 months ago

I am following this caliber comments and saw your post. Are the watches you listed all quartz watches? Quartz tends to switch the date over quickly and mechanical/automatics tend to take some time for the switchover to occur.

Peter Laurence-couzens
Peter Laurence-couzens
2 months ago
Reply to  Random Randy

Hello, the solar watch is quartz, the other watches described as quartz are indeed quartz, and the watches without the quartz in the description are , well, not quartz. There are many mechanical watches with date functions that click over at midnight, and indeed mine do, but as I’ve only had the “baby” alpinist for a short while I thought I’d come here to seek some definitive answer from someone(s) in the know.
Thanks.

Simon
Simon
1 month ago

Ah. No it varies but on that movement as MRQ56 says it can take from 11pm to 2pm to fully change. One tip with this movement. NEVER quick set the date when the hands are in the second half of the day. In other words. Move the hands manually until the date changes. Then move the hands to 6:30 am. Only then should you quick set the date. Not when the next pass of the… Read more »

Simon
Simon
1 month ago

Yes it does.

Peter Laurence-Couzens
Peter Laurence-Couzens
2 months ago

Some clarification. I’ve received an email from Seiko UK service centre regarding my 2 questions, and have been informed that the gradual date change, and the hand winding mode still being in operation when screwing the crown back down are normal functions of this movement. That’s good enough for me. I’m still amazed at the accuracy I’m getting with this movement. Very happy 🙂

William
William
1 month ago

je possede un SBDC055 alimenté par un 6R15 et j’ai chronométré la réserve de marche j’ai obtenu 62h20 la précision aussi est bien meilleure que celle annoncée

Simon
Simon
1 month ago

Having read all the comments and responded to a few I will post this in reference to the 6R35 and 6R35A: 1) the mainspring is NOT silicon. It’s metal. If you put your phone near a magnetic source sick as a mobile it will cause it to run fast. You need to demagnetise it. The kit to do this is £6 on eBay. 2) this movement is sensitive to how it is positioned when not… Read more »

Simon
Simon
1 month ago
Reply to  Simon

Ps. Excuse typos. The thing posted before I could correct them.

Eric O.
Eric O.
1 hour ago
Reply to  Simon

Well said, all of it.

Jacklab
Jacklab
1 month ago

I have read some comments where we talk about the magnetism and magnetization of the balance wheel … But none of you have noticed that in the photo at the bottom of the caseback, probably of the new Seiko Alpinist SPB117, a symbol in the shape of a horseshoe is represented , which is famously used as a symbol of magnetism. Do you know that this symbol indicates protection from the magnetisms that surround us… Read more »

Hi
Hi
14 days ago

My spb143j1 is getting +1 a day, Out of the box i was getting +15 but movement settled down over few weeks. Impressive since rolex promises same accuracy right? since this is my first ever seiko watch im Satisfied.

Julián
Julián
13 days ago

Any plastic parts?

Nick Kent
Nick Kent
10 days ago

Very accurate when worn daily, however if left unworn over a weekend looses accuracy by some margin , 30 secs plus, it’s a daily wearer movement

Hi
Hi
7 days ago
Reply to  Nick Kent

My spb143j1 gives 1+ wherethere on wrist or in drawer as long as its winded. Almost 3 days it can keep time.

trackback
Seiko SPB147: Who Needs the Black Bay 58? - FIFTH WRIST
9 days ago

[…] the 6R35 movement, you’re getting 70hrs PR, I don’t have a timegrapher however mine seems to be keeping pretty […]

66
0
Would love your thoughts, please comment.x
()
x