Seiko NH71 Movement: Gilt Skeleton Caliber Guide & Build (2026)
The NH71 is the one people mean when they say "the gold skeleton movement." It's the gilt-finished member of Seiko's skeleton automatic family, and it's one of my favourite calibers to drop behind an open dial — the warm gold bridges catch the light in a way the silver and grey versions don't. This guide covers what the NH71 actually is, how it compares to the NH70 and NH72, and how to build with it. And because a lot of bad information floats around about a so-called "NH71.5," I'll clear that up too.
What is the Seiko NH71?
The NH71 (full designation NH71A) is a skeletonized automatic movement made by Time Module Inc. (TMI), a subsidiary of Seiko Instruments. It's built on the same NH35A platform as the rest of the NH family, but the bridges and mainplate are open-worked so you can see the gear train, balance wheel and mainspring straight through the dial. The finish is gold/gilt plating, and on most units the rotor carries Côtes de Genève (Geneva stripes) — a small touch that reads far more expensive than the movement costs.
Because it shares the NH35A base, the NH71 does everything the workhorse NH35 does: it hacks (the seconds hand stops when you pull the crown, so you can set the time precisely) and it hand-winds (you can wind the mainspring manually through the crown). It runs at 21,600 bph, uses 24 jewels, and holds a power reserve of about 41 hours.
NH71 specifications
| Type | Skeletonized automatic |
| Base caliber | NH35A platform (Seiko / TMI) |
| Jewels | 24 |
| Frequency | 21,600 bph (3 Hz / 6 beats per second) |
| Power reserve | ~41 hours |
| Winding | Automatic + manual hand-winding |
| Hacking | Yes (seconds-hand stop) |
| Date | None |
| Finish | Gilt / gold plating, Geneva-stripe rotor |
| Dial size (modding) | 30.8 mm skeleton dials |
| Case fit | Any NH35-family case |
| Price at Nomods | $140 |
NH70 vs NH71 vs NH72: it's the same movement
This trips up a lot of new builders, so let me be blunt: the NH70, NH71 and NH72 are mechanically identical. Same NH35A base, same 24 jewels, same 21,600 bph, same ~41-hour reserve — and all three hack and hand-wind. There is no functional upgrade from one to the next. The only real difference is the finish colour.
| Movement | Finish | Looks best behind | Price |
|---|---|---|---|
| NH70 | Nickel (silver) | Silver and steel dials/cases | $150 |
| NH71 | Gilt gold, Geneva-stripe rotor | Gold or warm dials — also a great contrast pop | $140 |
| NH72 | Ruthenium (dark grey) | High-contrast skeleton dials | $150 |
Pick the colour that suits your dial and case. As it stands, the NH71 is actually the cheapest of the three, which makes the gold finish a bit of a bargain.
What about the "NH71.5"?
You may have seen the term "NH71.5" floating around — including in an older version of this very guide, which I've now corrected. Here's the truth: the NH71.5 is not a real caliber. Seiko has never made one, and there is no meaningful "hybrid" to build.
The myth usually claims you combine NH71 and NH72 parts to "add" hacking or hand-winding. But since the NH70, NH71 and NH72 are the same movement inside — all of them already hack and hand-wind — there is nothing to combine and nothing to gain. If you want a gold skeleton movement, you buy an NH71. If you want grey, you buy the NH72. That's the whole decision.
How to build with the NH71
Building with the NH71 is the same as any NH35-family build, with two things to watch:
- Dial size: skeleton movements take 30.8 mm dials, not the 28.5 mm dials used by the NH35/NH36. Use a skeleton or open-worked dial so the movement stays visible.
- Display caseback: half the point of a gilt movement is seeing it, so build into a case with a see-through caseback (every Nomods case includes one).
Everything else is standard: NH-compatible hands (1.50 / 0.88 / 0.20 mm fittings), an NH35-family case, and a movement holder sized for the NH3x family.
Parts you need
- Movement: NH71 Skeleton Automatic Movement — or the NH70 / NH72 if you prefer a different finish
- Dial: a 30.8 mm skeleton dial
- Case: any Seiko mod case with a display caseback
- Hands: a set of NH-compatible hands
New to this? Start with my step-by-step first-build guide, or browse complete Seiko mods if you would rather buy one already built.
Frequently asked questions
Does the NH71 hack?
Yes. The NH71 is based on the NH35A, so the seconds hand stops when you pull the crown, letting you set the time precisely.
Does the NH71 hand-wind?
Yes. You can wind the mainspring manually through the crown, in addition to the automatic rotor.
What's the difference between the NH71 and the NH72?
Finish only. Both are the same movement mechanically — the NH71 is gilt gold, the NH72 is ruthenium grey. Choose the colour that suits your dial.
Is the NH71.5 a real movement?
No. It's not an official Seiko caliber and there is no functional hybrid to build — the NH70, NH71 and NH72 already share identical mechanics.
Does the NH71 have a date?
No. It's a no-date skeleton movement. If you need a date window, use the NH35 (solid dial) instead.
