147 products
Seiko 7S26 / NH23 Parts
The NH23 and the 7S26 movements are quite similar because they are both simple, reliable automatic movements produced by Seiko Instruments Inc. (SII). However, the NH23 is a more modern version designed for external manufacturers (e.g., microbrands), while the 7S26 was exclusively used in Seiko watches. Here are the key differences and similarities:
Similarities
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Mechanical Base:
- Both are automatic movements without manual winding or hacking features.
- They share similar specifications:
- Beats per hour (BPH): 21,600.
- Power reserve: Approximately 40 hours.
- Number of jewels: 21.
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Use Case:
- Both are designed for entry-level, affordable watches.
- Renowned for their simplicity, reliability, and low maintenance.
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Day and Date Complication:
- Both movements feature a day-date function, often with the day displayed in two languages (depending on the watch).
Differences
| Feature | NH23 | 7S26 |
|---|---|---|
| Purpose | Designed for external manufacturers (microbrands, aftermarket). | Exclusive to Seiko watches. |
| Production | Modern version, still in production. | Discontinued, no longer produced. |
| Calibration | Basic settings, often adjusted by the manufacturer. | Pre-calibrated by Seiko for their watches. |
| Parts Availability | Easily available in aftermarket. | Harder to find due to discontinued status. |
| Rotor Branding | Unbranded or marked with "SII". | Seiko-branded. |
| Compatibility | Compatible with a wide range of watch cases. | Specific to Seiko watch cases. |
Advantages of the NH23 Over the 7S26
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Availability:
- The NH23 is still in production and readily available from aftermarket and wholesale channels.
- The 7S26 has been discontinued, making it harder to source complete movements or spare parts.
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Flexibility:
- The NH23 is widely used by microbrands and external manufacturers, offering greater versatility.
- The 7S26 was limited to Seiko watches, making it less adaptable for aftermarket use.
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Modernized Production:
- While functionally similar, the NH23 benefits from more modern production techniques, potentially offering improved consistency and reliability.
When to Choose Which?
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NH23:
- Best for new watches, microbrand projects, or aftermarket replacements.
- Ideal when you need a modern, widely available movement.
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7S26:
- Only relevant for repairing Seiko watches or vintage projects where using an original Seiko movement is essential.
Conclusion
The NH23 is essentially a modern, aftermarket-oriented version of the 7S26. The primary difference lies in availability and target audience: the NH23 is versatile and designed for broader applications, while the 7S26 is a classic Seiko movement that was exclusive to Seiko watches.
