The Seiko NH35 Movement: A Comprehensive Guide

The Seiko NH35 movement, part of the NH series, is produced by Seiko Instruments Inc. (SII). Introduced in the early 2000s, the NH35 quickly became popular due to its robustness and affordability.

It is a derivative of Seiko’s 4R35 movement, designed for the mass market while maintaining high standards of quality. The NH35 has been a favorite among microbrands and independent watchmakers, often seen as a reliable workhorse in the watch industry.

• Type: Automatic
• Jewels: 24
• Frequency: 21,600 vibrations per hour (vph) or 3 Hz
• Power Reserve: Approximately 41 hours
• Diameter: 27.40 mm
• Height: 5.32 mm
• Functions: Hours, minutes, seconds, date
• Accuracy: -20 to +40 seconds per day
• Hacking: Yes (seconds hand stops when the crown is pulled out)
• Hand-winding: Yes
• Calendar: Date display

The Seiko NH35 and the Miyota 8215 are both popular movements in the watchmaking industry, often used in affordable automatic watches. Here’s how they compare:

• Accuracy: The NH35 has an accuracy of -20 to +40 seconds per day, while the 8215 is rated at -20 to +40 seconds per day, making them similar in terms of precision.
• Frequency: Both movements operate at a frequency of 21,600 vph, resulting in a similar sweep of the seconds hand.
• Jewels: The NH35 features 24 jewels, while the 8215 has 21 jewels.
• Power Reserve: The NH35 offers a power reserve of approximately 41 hours, compared to the 42 hours of the 8215.
• Height: The NH35 is thicker at 5.32 mm, whereas the 8215 is slightly thinner at 5.67 mm.
• Hacking: The NH35 has a hacking feature, allowing the seconds hand to stop when setting the time. The 8215 does not have a hacking function.
• Hand-winding: Both movements allow for hand-winding.
• Date Function: Both movements include a date function, but the NH35 offers a smoother quickset date change mechanism.

The Seiko NH35 is featured in a wide range of watches from various brands, especially those known for offering value for money. Some well-known models using the NH35 include:

• Seiko 5 Sports
• Invicta Pro Diver
• Orient Ray II
• Vostok Amphibia

Setting the time and date on a watch with the Seiko NH35 movement is straightforward:

1. Pull the crown out to the first position. This allows you to set the date.
2. Turn the crown to set the desired date. Rotate clockwise to change the date.
3. Pull the crown out to the second position. This stops the seconds hand, allowing for precise time setting (hacking function).
4. Turn the crown to set the desired time. Rotate clockwise or counterclockwise to move the hour and minute hands.
5. Push the crown back in to start the movement. The seconds hand will resume moving, and your time is set.

The Seiko NH35 boasts several technical features that contribute to its popularity:

• Diashock Protection: Provides enhanced shock resistance.
• Unidirectional Winding: Efficiently winds the movement in one direction to maintain the power reserve.
• Durability: Constructed with high-quality materials to ensure long-term reliability.
• Compatibility: The NH35 is often praised for its compatibility with a wide range of aftermarket parts and ease of servicing.

The replacement price for a Seiko NH35 movement typically ranges from $40 to $70, depending on the supplier and region. This affordability, combined with its robust performance, makes it a go-to choice for both hobbyists and professional watchmakers.

While the Seiko NH35 is highly regarded, it does have a few shortcomings:

• Thickness: Its height of 5.32 mm can be a limitation for ultra-thin watch designs.
• Accuracy: The NH35’s accuracy range of -20 to +40 seconds per day is decent but not as precise as some higher-end movements.
• Rotor Noise: Some users report that the rotor can be relatively noisy during movement, which might be noticeable in quiet environments.

The Seiko NH35 is a widely acclaimed automatic movement known for its reliability and versatility.

Its widespread use across various watch brands attests to its status as a dependable workhorse in the world of watchmaking. Despite a few minor drawbacks, the NH35 remains a preferred choice for many watch brands.