# Comparison of Epson YN55a movement and Tianma NH35 movement



## sanmartinwatch (May 25, 2021)

Hi everyone, this is Liao Jiaming. Because the new crown pneumonia in Malaysia is not under control, the Tianmadu NH35a movement is out of stock in the overall market. The price can be said to be the rocket's rising speed, from 130rmb at the beginning of the year to 250rmb now. The key issue is that we can only find goods in small batches. So everyone is looking for a replacement movement that can replace the NH35a movement. We plan to replace some of the watches with the YN55a movement.

Let me talk about the similarities and differences between the two movements. Both belong to Seiko's movements. The NH35a movement is produced by Tianmadu, mainly for the mass market; the YN55a movement is produced by Epson, mainly for supply. The big brands have no external sales. According to the movement data, the two movements are basically the same, with some minor differences (the diameter of the movement is the same, the thickness difference is 0.05mm, and the position difference in Bazhong is 0.1mm). The purpose of replacement is achieved by changing a small part of the accessories.















Today we evaluate the YN55A movement, mainly through two aspects of comparison. On the one hand, it is compared with the functional structure and parts of the NH35a movement. On the other hand, it is the test of the YN55a movement.















Sorry that my video is in Chinese. I will introduce you to the main meaning of what I said. I asked our assembler to disassemble the two movements NH35a and YN55a and compare the structure and parts of the two movements. Explain the similarities between the two movements;
Then take out a package of YN55a movement that has not been opened, and randomly take out five of them to observe the movement time on the calibrator. By observing the movement time, it is concluded that the movement time of the YN55a movement is very good. Through the tests of these movements, the YN55a movement is better than the NH35a movement. So I came to the conclusion that it is a very good choice to replace the NH35a movement


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## mleok (Feb 16, 2010)

Is it correct to say that the S. Epson YN55a is basically a version of the Orient F6922 movement that is made available to third-parties? These are the versions which hack and handwind?


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## sanmartinwatch (May 25, 2021)

mleok said:


> Is it correct to say that the S. Epson YN55a is basically a version of the Orient F6922 movement that is made available to third-parties? These are the versions which hack and handwind?


There should be nothing wrong, but this movement should be Orient, which was later received by Seiko and Epson continued to produce it. Supply to some well-known watch brands


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## mrwomble (Dec 28, 2011)

Calling on @HoustonReal - would love to know your thoughts on the YN55 or anything you could share about it?


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## arclight* (Jan 14, 2011)

Does the stem on the Epson YN55A movement that you now use in your Bronze Pilot SN030-Q have a ghost date position or does it go directly from the wind to the set position?


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## arclight* (Jan 14, 2011)

sanmartinwatch said:


> There should be nothing wrong, but this movement should be Orient, which was later received by Seiko and Epson continued to produce it. Supply to some well-known watch brands


Does the stem on the Epson YN55A movement that you now use in your Bronze Pilot SN030-Q have a ghost date position or does it go directly from the wind to the set position?


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## eple (Jun 1, 2011)

I have a San Martin watch with a YN55A movement, which has a ghost date position.


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## arclight* (Jan 14, 2011)

eple said:


> I have a San Martin watch with a YN55A movement, which has a ghost date position.


Thank you!


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## IkariGendo (Feb 8, 2017)

Why not use a movement with no date for watches without a date window?


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## manolito (Sep 11, 2020)

sanmartinwatch said:


> Hi everyone, this is Liao Jiaming. Because the new crown pneumonia in Malaysia is not under control, the Tianmadu NH35a movement is out of stock in the overall market. The price can be said to be the rocket's rising speed, from 130rmb at the beginning of the year to 250rmb now. The key issue is that we can only find goods in small batches. So everyone is looking for a replacement movement that can replace the NH35a movement. We plan to replace some of the watches with the YN55a movement.
> 
> Let me talk about the similarities and differences between the two movements. Both belong to Seiko's movements. The NH35a movement is produced by Tianmadu, mainly for the mass market; the YN55a movement is produced by Epson, mainly for supply. The big brands have no external sales. According to the movement data, the two movements are basically the same, with some minor differences (the diameter of the movement is the same, the thickness difference is 0.05mm, and the position difference in Bazhong is 0.1mm). The purpose of replacement is achieved by changing a small part of the accessories.
> View attachment 16114441
> ...


a tabulation of *YN55A vs NH35A* key _*features*_ and key *performance results* will be much appreciated. regards.


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## BigHowie (Nov 12, 2021)

sanmartinwatch said:


> Hi everyone, this is Liao Jiaming. Because the new crown pneumonia in Malaysia is not under control, the Tianmadu NH35a movement is out of stock in the overall market. The price can be said to be the rocket's rising speed, from 130rmb at the beginning of the year to 250rmb now. The key issue is that we can only find goods in small batches. So everyone is looking for a replacement movement that can replace the NH35a movement. We plan to replace some of the watches with the YN55a movement.
> 
> Let me talk about the similarities and differences between the two movements. Both belong to Seiko's movements. The NH35a movement is produced by Tianmadu, mainly for the mass market; the YN55a movement is produced by Epson, mainly for supply. The big brands have no external sales. According to the movement data, the two movements are basically the same, with some minor differences (the diameter of the movement is the same, the thickness difference is 0.05mm, and the position difference in Bazhong is 0.1mm). The purpose of replacement is achieved by changing a small part of the accessories.
> View attachment 16114441
> ...


Hi. Why cant you adopt the PT5000 high beat rate movement as that seem an obvious higher quality alternative. The only thing with the YN55 that puts me off is it has less jewels therefor wont last as long or be as reliable as the nh35. Im sure buyers would rather pay that little bit extra for a trusted reliable high beat movement. I know that a movement is a deal breaker for me, being a watch collector and wont touch a watch with a miyota 8215 movement inside. The PT500 is an old adopted eta movement and now being produced by a decent japanese company.


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## Andrey_31 (Sep 16, 2021)

Spoiler



[QUOTE = "sanmartinwatch, post: 53991419, member: 1493784"]
Всем привет, это Ляо Цзяминь. Новая коронная пневмония в Малайзии не находится под контролем, движение Тианмаду NH35a отсутствует на общем рынке. Можно сказать, что цена - это скорость нарастания ракеты с 130 юаней в начале года до 250 юаней сейчас. Ключевой вопрос в том, что мы можем найти товары только небольшими партиями. Таким образом, каждый ищет замену механизму, который мог бы заменить механизм NH35a. Мы планируем заменить некоторые часы на механизм YN55a.

Позвольте мне поговорить о сходствах и различиях между двумя движениями. Оба принадлежат движениям Seiko. Механизм NH35a создается в основном для массового рынка; механизм YN55a производится Epson, в основном, для поставок. У крупных брендов нет внешних продаж. Согласно данным о механизме, эти два механизма в основном одинаковы, с небольшими различиями (диаметр механизма одинаков, разница в толщине составляет 0,05 мм, а положение в Бажонг составляет 0,1 мм). Цель достигается замены заменой небольшой части аксессуаров.
[ATTACH = полный] 16114441 [/ ATTACH] [ATTACH = полный] 16114442 [/ ATTACH]
Сегодня мы оцениваем движение YN55A в основном с помощью двух сравнений. С одной стороны, его сравнивают с функциональной структурой и деталями механизма NH35a. С другой стороны, это тест механизма YN55a.
[ATTACH = полный] 16114443 [/ ATTACH] [ATTACH = полный] 16114444 [/ ATTACH]
Извините, что мое видео на китайском языке. Я познакомлю вас с основным смыслом сказанного. Я попросил нашего сборщика разобрать два механизма NH35a и YN55a и изменить структуру и детали этих двух механизмов. Объясните сходство между двумя движениями;
Затем выньте упаковку механизма YN55a, которая не была открыта, и случайным образом выньте пять из них, чтобы измерить время движения на калибраторе. Наблюдая за временем движения, можно сделать вывод, что время движения механизма YN55a очень хорошее. По результатам испытаний этих механизмов, механизм YN55a лучше, чем механизм NH35a. Поэтому я пришел к выводу, что это очень хороший выбор для замены механизма NH35a.
[MEDIA = youtube] LCFI7GP54ls [/ MEDIA]
[/ ЦИТИРОВАТЬ]


Do you have technical documentation for this mechanism? Information may be needed by moderators and developers. From the image you are showing, you have a PDF file. If you don't want to share, tell me at least what are the dimensions of the hand holes? or is it a secret? then why this mechanism? I do not want it!


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## happyjaya (Mar 10, 2012)

made in where ?


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## an0nemus (Jul 4, 2018)

Thanks for this! Can I use NH35 watch hands on my YN55A watch?


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## Kalae (Jan 7, 2022)

an0nemus said:


> Thanks for this! Can I use NH35 watch hands on my YN55A watch?


I'd like to know the same


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## ^Gurthang54 (Oct 5, 2018)

The Epson YN movements are identical to the Orient F67/F69 movements which can use Seiko 7S,4R,NH sized hand-sets.

BTW, the YN has the same specs as the F6; +25/-15 sec/day which is better than the Seiko NH; +45/-25 sec/day.


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## Skyjuice (Sep 7, 2018)

Very interesting! Where can I get one of this YN055a movement if I need a replacement?


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## sanmartinwatch (May 25, 2021)

44.85US $ 31% OFF|Time Module Mechanical Movement Yn55a Automatic Self-wind Movt Replacement Steel Date Display 3 Hands 21600 Vph 22 Jewels Yn55 - Watch Movement - AliExpress


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www.aliexpress.com






Skyjuice said:


> Very interesting! Where can I get one of this YN055a movement if I need a replacement?


Sir, yes, you can buy it in our accessories store now. 😊 

YN55: 44.85US $ 31% OFF|TIME MODULE Mechanical Movement YN55A Automatic Self Wind Movt Replacement Steel Date Display 3 Hands 21600 VPH 22 Jewels YN55| | - AliExpress
NH35: 44.85US $ 31% OFF|Japan Original Seiko NH35 NH35A 3H AUTO Mechanical Movement 21600 VPH White Date Display Durable Accurate Watch Movt Replace| | - AliExpress


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## sanmartinwatch (May 25, 2021)

an0nemus said:


> Thanks for this! Can I use NH35 watch hands on my YN55A watch?





Kalae said:


> I'd like to know the same


Sir, their matching case backs are different. So no, they won't be compatible.


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## Dave51 (Mar 25, 2019)

sanmartinwatch said:


> Sir, their matching case backs are different. So no, they won't be compatible.


That does not impact the hand size. The hand hole size of the Orient movements are the same as the Seiko NH movements. Most hands for NH movements are sized for Seiko-sized dials. Orient dials are typically larger. Independent companies like San Martin and others will also have varying dial sizes that may or may not match well with available watch hands that fit the NH movements (even though the hole sizes will match).


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## gear1box (Dec 24, 2020)

BigHowie said:


> Hi. Why cant you adopt the PT5000 high beat rate movement as that seem an obvious higher quality alternative. . . . . The PT500 is an old adopted eta movement and now being produced by a decent japanese company.


Howie --

i have two Orients (well Orient Stars; YN55 movement with a power reserve complication) and, golly, now four PT5000s (in addition to bunch of other ETAs like Powermatic's, 7753s, 2896, etc). i'd offer the following:

YN55 is a somewhat more modern design than a 2824 or NH35: it was re-engineered about 2016 specifically for advanced manufacturing. I wouldn't be too concerned about jewel counts.
It is very easy to regulate to well better than COSC accuracy; with the same regulation i'd call accuracy a wash with the PT5000s.
Compared to my PT5000s, my YN55s wind more noticeably more efficiently on my winders and hold a solid ten hours or so more PR. 
Having owned both for some years now i'd say that they are largely a wash from a consumer perspective. i have owned NH35s -- none now -- and i found them less accurate than either of these movements.

-- gary ray


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## ^Gurthang54 (Oct 5, 2018)

You got it Dave, Seiko 7S-4R-NH and NE (I think) are all compatible w/ Orient 46-F6/7/8 movements it's the hand lengths that vary. As you point out Orient diver dials are generally larger than Seiko divers. That said, until the dial size is posted it's difficult to know which hand-set will fit any given model. Most SKX hand-sets do not look pleasing on the Mako/Ray/Kamasu. OTOH Sumo & Samuri hand-sets may work as the dials are larger. 

Wouldn't it be great if makers supplied dial diameters and hand-set lengths, life for modders would be much simpler.


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