How does the NH35 movement work? A complete guide to understanding the heart of your Seiko watch

¿Cómo funciona el movimiento NH35? Guía completa para entender el corazón de tu reloj Seiko

Introduction

The NH35 movement is one of the most popular automatic movements in the world. Known for its precision, reliability, and ease of maintenance , this caliber has become the foundation of many high-quality watches. In this article, you'll discover how the Seiko NH35 movement works , its advantages, and how to properly care for it. You'll also understand why it's so widely used in the world of Seiko mods .

What is the NH35 movement?

The NH35 movement (also known as caliber NH35A) is a Japanese automatic movement manufactured by Seiko Instruments Inc. (SII) . It belongs to the same family as Seiko's famous caliber 4R35 .

This mechanism operates without a battery , harnessing the natural movement of your wrist to wind the mainspring. It also allows for manual winding and features a hacking function (the seconds hand stops when setting the time).

Some technical specifications:

  • Frequency: 21,600 vph (3 Hz)

  • Power reserve: approximately 41 hours

  • Jewelry: 24 rubies

  • Type: Automatic with manual winding

  • Functions: Hour, minutes, seconds and date

These characteristics make the Seiko NH35 movement ideal for everyday watches and customization projects.

How the Seiko NH35 movement works

The operating principle is simple but fascinating:

  1. The rotor , an oscillating mass that rotates when the wrist moves, loads the mainspring .

  2. This dock stores the energy that powers the entire system.

  3. Energy is transmitted through a gear train , which regulates the flow thanks to the exhaust and the flywheel .

  4. The result: a continuous and stable movement of the hands.

Thanks to its bidirectional charging system , the NH35 movement maintains a constant power reserve even with moderate use. Furthermore, its modular design facilitates repair and adjustment by watchmakers or advanced enthusiasts.

Advantages of the NH35 movement

The Seiko NH35 movement is appreciated by both professionals and enthusiasts for several reasons:

  • High reliability: It is built to last and withstand daily use.

  • Solid accuracy: offers a margin of error of ±20 seconds/day, adjustable with good maintenance.

  • Easy maintenance: spare parts are inexpensive and easy to find.

  • Versatility: It adapts to a wide variety of designs and brands.

  • Excellent value for money: combines professional performance with a very competitive cost.

These advantages explain why so many independent brands and modders choose it as the basis for their custom watches.

How to care for your watch with NH35 movement

Keeping your watch in good condition is key to preserving its accuracy and longevity:

  • Use it regularly to keep the system charged.

  • If you don't use it for several days, wind it manually by turning the crown.

  • Avoid strong impacts or magnetic fields , as they can affect the regulation.

  • Do not adjust the date between 9:00 PM and 2:00 AM , when the calendar mechanism is active.

  • Perform a technical service every 3 to 5 years for cleaning and lubrication.

With these basic care instructions, your Seiko NH35 movement watch will accompany you without problems for decades.

Conclusion

The NH35 movement is the perfect balance of precision, reliability, and affordability. Its robust design, versatility, and ease of maintenance make it an ideal choice for both commercial watches and Seiko mod projects.

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