Seiko NH35A Movement Guide

Seiko NH35A Movement Guide

Hey everyone. Today I’ve put together a guide to the popular Seiko NH35 movement. This movement is typically found in many affordable watches from brands like Invicta, Seiko, Vostok, LumTec, Spinnaker Hull, and Minus-8.


Seiko (SII) Caliber) NH35 Specifications

Below is a specifications list for the NH35A movement, also known simply as the NH35)

Manufacturer: Seiko

Caliber Number: NH35A (NH35)

Movement Type: Automatic

Jewels: 24

Vibrations Per Hour: 21,600 (6 ticks per second)

Accuracy: -20/+40 seconds per day

Power Reserve: 41 hours when fully wound

Shock System: Diashock

Winding Direction: Bi-directional

Hacking: Yes

Height: 5.32mm (total height)

Diameter: 27.40mm (outside) / 29.36mm (casing)

Functions: Hours, minutes, central seconds, date calendar

Country of Manufacture: Japan/Malaysia


Why is the NH35A such a popular movement?

The NH35 is effectively an unbranded version of the Seiko caliber 4R36 movement, a watch movement I’ve reviewed in the past. The 4R36 is found in the next generation Orange Monster, Seiko Turtle, and many watches from the SAR collection.

The Seiko NH35 movement is hand-windable and features a hacking function. A hacking function means the second hand stops when the crown is pulled out.

This Seiko NH35A movement is known to be a reliable and fairly accurate automatic movement which is why it has become one of the most popular automatic movements for many affordable watch brands. Seiko are known for being one of the best watch brands under £500.  Most notably is Invicta, who features the Seiko NH35A movement in a large range of their automatic watches, you’ll find many cool watches for teens manufactured by this brand.

How to set the time on a Seiko SII NH35

Setting the time on the Seiko NH35 movement requires 3 simple steps:

  1. Pull the crown out to the second click position
  2. Turn the crown to set hour and minute hands (be sure to check AM / PM is correctly set)
  3. Push the crown back into the normal position

How to set the date on a Seiko NH35A movement

Setting the date on this movement is just a simple as setting the time:

  1. Pull out the crown to the first click position
  2. Turn the crown to alter the date setting
  3. Push the crown back into its normal position

Note that you shouldn’t set the date between the 9:00 PM and 4:00 AM time on the watch, this is because it can cause a malfunction on the timepiece.

How to wind up the mainspring

To fully wind up the watch turn the crown a minimum of 55 times (Be careful not to overwind your watch as this can damage the movement, if you feel resistance stop rotating the crown). You can fully wind up the movement by turning the ratchet wheel screw 8 times.

Useful links regarding the Seiko NH35A movement


I’d love to hear what your experience with the Seiko NH35A movement has been like. Comment below letting me know what watch you have that features in and how accurate you’ve found it to be.

4 thoughts on “Seiko NH35A Movement Guide”

  1. Hi! Great source of info on the NH35A. I’ve recently bought an Invicta 8926OB that uses this movement. Works great. And I’ve corroborated that mine is 2.5s to 3.5s slower every 24hs when using it regularly on my wrist and 4.8s to 7.5s when keeping it that day in my watch box. But last night I removed its NATO strap (yes, I’ve gone Bond with it) and left it standing on its head (i.e. standing on the 12) ans today it’s almost 18 seconds slower! Wow! I’m wondering, then, if this is normal for this movement in this position or if I might start to believe mine is out of whack! Also, what position others find make the NH35A run faster. That way I can auto-regulate it. Thanks, again!

  2. The Seiko NH35A movement is fairly reliable. Only 1 minute late daily which is not bad.

  3. The NH35A is a brilliant movement. Could you show examples of more watches that feature it?

  4. Want to dive to 1000m with an inexpensive watch? Neymar. Go to their web site or on Amazon. They use the Seiko NH34 movement.

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