Seiko SII caliber NH38A Drawings

Seiko (SII) Caliber NH38A

Seiko SII caliber NH38A Drawings

ManufacturerSeiko (SII, TMI)
Caliber NumberNH38A
Movement TypeAutomatic
Jewels24
Vibrations Per Hour
21,600 bph
Shock System?Yes
Power Reserve
41 hours
Winding Direction
Bi-directional
Hacking?Yes
Diameter27.40mm (outside) / 29.36mm (casing)
Height5.32mm
FunctionsHours, minutes, central seconds
Country of ManufactureJapan/Malaysia
Known Brands
Invicta (add more in the comments below)

keepthetime-468-60

 

 

The Seiko caliber NH38A is very similar to the popular caliber NH35A.The NH38 series is often found with an open balance wheel at 9:00 on the dial.

Time Module (TMI) claims an accuracy rating of -20~+40 seconds per day.

What is the difference?

Unlike the NH35A, the NH38A is a basic three hand watch and does not have a day or date complication.

Japan or Malaysia?

The complete Japanese-made caliber number is NH38A3J. For the Malaysia variant, the number is NH38A3M.

The large photo below is of a Seiko NH38A movement in an Invicta 22744 watch.

 

Seiko SII caliber NH38A in an Invicta watch

Submitted by Nathaniel B.


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Tracey Deel
Tracey Deel
6 years ago

I have this movement in an ARAGON, was Android by Wing Liang.

Jürgen Albers
Jürgen Albers
5 years ago
Doug
Doug
5 years ago

Helm Khuraburi uses the nh38a

Paul Overby
Paul Overby
2 years ago
Reply to  Doug

I have the Helm Khuraburi. So far, I am experiencing around +5 second per day with the NH38.

Joris
Joris
5 years ago
Zoroff
Zoroff
4 years ago

Armourlite also uses NH38

Will
Will
4 years ago

I have this watch in a Momentum Morioka watch.

Bert
Bert
4 years ago
Reply to  Charles Laigo

My Phoibos Wavemaster is a great watch but the Seiko movement in it is at least 10 seconds a day slow, a common issue. I wish brands would regulate these movements before shipping!

Rich
Rich
4 years ago

My Giorgio Fedon has this movement.

W
W
4 years ago

Traska Freediver

Øyvind
Øyvind
4 years ago

Used by Giorgi Fedon 1919

Roger Ingram
Roger Ingram
3 years ago

Also found in Traska watches

Jeff Summers
Jeff Summers
2 years ago
Reply to  Roger Ingram

Hey I am a huge fan of yours. Had one of your Jupiter trumpets for years. You should check out my YouTube channel at https://www.youtube.com/channel/UCnGYxMEr5niyVeTjduwLBpw
Awesome you are a watch fan too!!

Best,
Jeff Sumners

koimaster
koimaster
3 years ago

I love coming to this site to learn more about movements and to share.

Brian Centeno
Brian Centeno
1 year ago
Reply to  Caliber Corner

I too enjoy the heck out of this site. Is there any chance that some of the Chinese GMT and higher beat rate movements such as the Hangzhou 6460 can be included? I see the PT5000 here. Great information!!!

Brett
Brett
10 months ago
Reply to  koimaster

Me too. Now I learned to better appreciate watches more for their movement than their looks. I love coming to this site. I learn something new every time.

Rudy
Rudy
3 years ago

There is a typo in the table box.
Malaysia not Maylasia. 🙂

Remco
Remco
3 years ago

This movement is also used in the limited edition TW Steel’s Son of Time MST6.

evansna
evansna
2 years ago

Aquacy Cave Diver uses as well

trackback
Vario Empire Tuxedo – White & Gold – Beans & Bezels
2 years ago

[…] doesn’t work for you, you can also look at the automatic variant of this model that houses a Seiko NH38A. This comes at the cost of an additional 0.5mm of case thickness. In my opinion, the hand-wound […]

GreyMisha
GreyMisha
2 years ago

My invicta Master of the oceans uses this Caliber too. Very useful webpage. Thanks

Chris
Chris
2 years ago

In Zum watch R1
(In kikstarter actually)

justin hanson
justin hanson
2 years ago

vario is also using this movement

trackback
RZE Endeavour – Beans & Bezels
2 years ago

[…] watch uses a Seiko NH38A movement, so no date complication or a ghost date position. For the price, and given the […]

Áron
Áron
1 year ago

Villandry uses NH38. They say.

trackback
Presentación Vanbanner Parkingmaster - SaFonaGastroCrono
1 year ago

[…] motor del Parkingmaster no es el Roadster 2.0 de Tesla, sino el práctico NH38, primo sin fecha del ubicuo NH35. Al igual que el NH35, se trata de un calibre que oscila a 21.600 […]

Alister Hill
Alister Hill
1 year ago

Wearing a Reign ‘Bauer’ that arrived today, with this movement (so the website says). No prizes for guessing that I didn’t pay the MSRP for it! It is a nice watch, though.

https://reignwatches.com/products/reirn6000?variant=35116922208423

Stefan Vos Carrasco
Stefan Vos Carrasco
1 year ago

Ví este movimiento en un reloj Megir.

trackback
Presentación Vario 1918 Trench Watch - SaFonaGastroCrono
1 year ago

[…] con este ejemplar. Las versiones “Medic” equipan el calibre automático SEIKO NH38A, una versión sin fecha del archiconocido calibre […]

Glenn Williams
Glenn Williams
1 year ago

Cincinnati Watch Company “Cincinnatus” field watch.

Zio
Zio
1 year ago

I have it in the Aerotec ACE

Skidpalace
Skidpalace
1 year ago

Is this movement compatible with cases made for NH35/36, such as SKXs and the like?

José Carvalho
José Carvalho
1 year ago

I guess I am lucky… Extraordinary movement!
I have several higher end automatic movements (including Swiss!) and by far this is the most accurate one, about 20 seconds (+) per month!
I have it in a Briston Clubmaster Iconic Automatic and it is now my daily watch!
I am truly amazed how accurate it is!!!

craig
craig
1 year ago

is the NH38 handwinding. and is there any major disadvantages to having the malaysian movement?

Brett
Brett
10 months ago
Reply to  craig

Read the page. Yes, it’s hand winding. I have a Malaysia made with a date and it’s great. It’s the same movement just made in another place.

Roy Benny
Roy Benny
1 year ago

I just saw a brand of racing watches called ZUM that uses this movement as a regulator watch.

trackback
Presentación Nodus Sector Dive - SaFonaGastroCrono
1 year ago

[…] no es un reloj ostentoso, ni su movimiento. Batiendo a 21.600 vph (3 Hz), lo impulsa un SEIKO NH38 automático. Esta versión sin fecha significa que no hay posición fantasma en la corona. También […]

Dirk
Dirk
1 year ago

Bering mentions on their website that the movement of a BERING Vitus 1728 has been developped with Miyota, still this watch has the NH38A (SII) in it

Chris
Chris
9 months ago
Reply to  Dirk

Same with a Bering 16743-307 watch I own. The Vitus 1728 is the Miyota movement they are referring to. Looks like they chose a better movement with the NH38A. They just need to update the website. -1 second per day for mine. I love it.

trackback
Presentación Namica Shirahama Dive Watch - SaFonaGastroCrono
1 year ago

[…] Shirahama equipa el calibre SEIKO NH38. Se trata de la versión sin fecha del popular NH35, un verdadero “caballo de batalla” […]

William Waddell
William Waddell
11 months ago

Islander Watch #ISL-82 uses this caliber.

trackback
Proyecto Flieger Económico - SaFonaGastroCrono
10 months ago

[…] este caso recurrí a eBay para adquirir un NH38A de SEIKO por €47 (con envío desde la UE). Debo remarcar que el precio de los calibres de la […]

trackback
3 Лучших Механических Часов из Дерева (2022) — Wrist Watch Everywhere
10 months ago

[…] Внутри часов находится японский часовой механизм Seiko NH38-3, 24 искусственных драгоценных камня, а также пружина с запасом хода в 41 час (источник). […]

Sergio Luiz Sant Anna
Sergio Luiz Sant Anna
8 months ago

Züm Watches is announcing an automotive-themed regulator. The self-winding rotor has design of a race car steering wheel.

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Alex
Alex
6 months ago

Addiesdive AD2103

Magnus Axelsson
Magnus Axelsson
3 months ago

The RZE Valour 38 uses this movement.

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