Here's a revised version of your Seiko NH35 overview:
Seiko NH35 Automatic Movement Overview
The Seiko NH35 is a widely respected automatic (self-winding) mechanical movement known for its reliability, durability, and affordability. Designed by Seiko Instruments Inc. (SII), it is a favorite among microbrands and affordable watchmakers. Below is a detailed breakdown of its key features, specifications, and comparisons with similar movements.
1. Overview
- Type: Automatic mechanical movement (self-winding with manual winding capability).
- Features: Hacking (seconds hand stops when setting), quickset date, and bi-directional rotor winding.
- Popularity: Commonly used in affordable dive watches, microbrands, and modding communities.
- Origin: Manufactured in Japan or Malaysia, depending on the production batch.
2. Key Specifications
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Dimensions:
- Diameter: 27.4 mm
- Height: 5.32 mm
- Weight: Approximately 21 grams (varies slightly with rotor design).
- Jewels: 24 jewels for reduced friction and improved longevity.
- Frequency: 21,600 vibrations per hour (vph) or 3 Hz.
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Accuracy:
- Factory range: -20 to +40 seconds per day.
- Post-regulation: Can achieve ±10 to ±15 seconds per day.
- Power Reserve: 41 hours when fully wound.
- Complications: Quickset date.
- Winding Mechanism: Bi-directional automatic winding with manual winding capability.
3. Durability and Maintenance
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Durability:
- Built for robustness, making it ideal for everyday use.
- Equipped with Diashock technology for shock resistance.
- Reliable in temperature ranges of -10°C to +60°C.
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Maintenance:
- Requires servicing every 5–7 years for optimal performance.
- Affordable replacement cost (typically $40–$60).
- Easily serviced due to its simple design and widespread use.
4. Key Features
- Hacking Function: Allows the seconds hand to stop for precise time setting.
- Hand-Winding: Supports manual winding, a feature not found in older Seiko movements like the 7S26.
- Quickset Date: Adjusts the date without cycling through 24-hour time.
- Bi-Directional Rotor: Enhances efficiency by winding the movement in both directions of rotor spin.
5. Comparison with Peer Movements
The Seiko NH35 competes with several other entry-level automatic movements, including the Miyota 8215, ETA 2824-2, and the PT5000, which is often used in higher-end microbrand watches. Here’s how the NH35 stacks up against its peers:
| Feature | Seiko NH35 | Miyota 8215 | ETA 2824-2 / SW200 | PT5000 |
|---|---|---|---|---|
| Jewels | 24 | 21 | 25 | 28 |
| Frequency | 21,600 vph | 21,600 vph | 28,800 vph | 28,800 vph |
| Accuracy (Factory) | -20/+40 sec/day | -20/+40 sec/day | -12/+30 sec/day | -20/+40 sec/day |
| Hacking | Yes | No | Yes | Yes |
| Power Reserve | ~41 hours | ~42 hours | ~38 hours | ~48 hours |
| Winding Direction | Bi-directional | Uni-directional | Bi-directional | Bi-directional |
| Cost | ~$40–$60 | ~$40–$60 | ~$150+ | ~$80–$120 |
Highlights:
- The NH35 outshines the Miyota 8215 with hacking and better regulation potential.
- While less precise and refined than the Swiss ETA 2824-2, it’s significantly more affordable and easier to service.
6. Applications
The NH35 is commonly found in:
- Microbrand Watches: Its reliability and low cost make it a go-to for independent brands.
- Dive Watches: Trusted for its robustness and water-resistance (when cased properly).
- Custom Mods: Popular among enthusiasts for aftermarket customization.
7. Pros and Cons
Pros:
- Affordable and reliable for everyday use.
- Hacking, hand-winding, and quickset date features.
- Durable and long-lasting, with easy servicing.
- Compatible with a wide variety of watch cases.
Cons:
- Factory accuracy range may require regulation for optimal performance.
- Slightly thicker than some competitors like the Miyota 9015.
- Rotor noise, though minimal, may be noticeable in some cases.
8. Watches Featuring the NH35
The NH35 is a staple in many affordable and mid-range watches, including:
- Seiko Mods: Frequently used in custom builds.
- Microbrands: Found in brands like Tandorio,Corgeut,Cadisen etc.
- Dive Watches: Used in durable, water-resistant timepieces.
9. Conclusion
The Seiko NH35 is a workhorse movement that offers outstanding value for money. Its combination of durability, reliability, and ease of servicing makes it a favorite for both watchmakers and enthusiasts. While it may lack the refinement of higher-end Swiss movements, it excels as an affordable and dependable option for everyday use.
If you’re considering a watch powered by the NH35, you can be confident in its long-term performance and versatility.
