NH70 Skeleton Automatic Movement
- In stock, ready to ship
Complete Your Build
The Seiko NH70 is the entry-level skeleton movement in the NH family. Manufactured by TMI (Time Module Inc.), a subsidiary of Seiko Instruments, the NH70 features open-worked bridges in a natural silver finish that expose the movement’s inner mechanics through a skeleton dial. It shares the 21,600 bph frequency, 24 jewels, 41-hour power reserve, hacking, and hand-winding of the solid NH35 family, but trades the date complication for the open-worked architecture that defines skeleton watches.
Specifications
| Specification | Detail |
|---|---|
| Caliber | Seiko NH70A |
| Type | Automatic Skeleton |
| Frequency | 21,600 bph (6 beats per second) |
| Jewels | 24 |
| Power Reserve | 41 hours |
| Hacking | Yes |
| Hand-Winding | Yes |
| Date | No |
| Skeleton | Yes (open-worked bridges) |
| Bridge Finish | Silver / natural |
| Stem Position | 3 o’clock |
| Rotor | Bidirectional |
Compatibility
The NH70 fits every Nomods case: Royal Oak 37 mm, Royal Oak 41 mm, Petrichor, and Seikonaut. To see the open-worked bridges, you need a skeleton dial — a dial with cutouts or transparent sections that reveal the movement underneath. Pairing the NH70 with a solid dial hides the skeleton architecture entirely, which defeats the purpose of choosing this caliber over the less expensive NH38.
Dial sizes: 28.5 mm skeleton dials for the Royal Oak 37 mm and Petrichor cases · 30.8 mm skeleton dials for the Royal Oak 41 mm and Seikonaut cases
Hands: All Nomods hands are compatible with the NH70 skeleton movement. Crown sits at 3 o’clock.
What’s Included
- Seiko NH70A skeleton movement (fully assembled with rotor)
- Stem
- Movement specification sheet
Why This Movement
The NH70 is the most affordable way to get a genuine Seiko skeleton movement into your build. The natural silver bridge finish has a clean, industrial look that pairs well with silver and gunmetal cases. If you want the open-worked skeleton aesthetic without committing to the premium gold or dark bridge finishes of the NH71 and NH72, the NH70 is the right starting point. Nomods uses the NH70 in entry-level skeleton builds where the customer wants visible mechanics at a lower price point.
Frequently Asked Questions
What is the difference between the NH70 and NH72?
Both are skeleton movements with the same 21,600 bph frequency, 24 jewels, and 41-hour power reserve. The difference is the bridge finish: the NH70 has natural silver bridges, while the NH72 has dark-plated (black) bridges. The NH72 creates a more dramatic contrast when viewed through a skeleton dial, while the NH70 has a cleaner, more industrial appearance. The NH71 is the third option, featuring gold-plated bridges.
Does the NH70 need a skeleton dial?
You need a skeleton dial to see the open-worked bridges that make the NH70 a skeleton movement. A skeleton dial has cutouts or transparent sections that reveal the movement underneath. You can technically install a solid dial, but the skeleton architecture will be completely hidden, and you would be better served by the less expensive NH38 (no-date) or NH35 (with date).
How accurate is the NH70 skeleton movement?
The factory specification is ±20 seconds per day, the same as the solid NH35 family. The open-worked bridges are purely aesthetic — they do not affect the timekeeping mechanism. Accuracy can be improved through regulation by a watchmaker.
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