Miyota 8215 vs 9015 vs Seiko NH35: which budget automatic movement is better?

The Miyota 9015 is the best of the three: it beats faster, it is about 1.8 mm thinner, and Miyota gives it a tighter accuracy tolerance than the 8215. The Seiko NH35 and the Miyota 8215 are closer to each other, but the NH35 stops its seconds hand when you pull the crown, which WatchScanning says the 8215 doesn't do.

Last checked 1 November 2026. Figures are from the makers' own pages where they publish them; the sources are listed at the end.

All three are automatic movements from Japanese makers, sold to many small watch brands. Lume & Lug sells watches with the Miyota 8215 and 9015 and none with the NH35, so weigh our view with that in mind.

The specs side by side

Miyota 8215 Miyota 9015 Seiko NH35
Beat rate 21,600 vph (6 steps a second) 28,800 vph (8 steps a second) 21,600 vph (6 steps a second)
Jewels 21 24 24
Power reserve About 42 hours About 42 hours About 41 hours
Rated accuracy −20 to +40 seconds a day −10 to +30 seconds a day −20 to +40 seconds a day (sellers' figure; we found no Seiko sheet)
Posture difference Under 50 seconds Under 30 seconds Not found
Movement height 5.67 mm 3.90 mm 5.32 mm (Caliber Corner)
Hand winding Yes Yes Yes
Seconds stop when you pull the crown Miyota lists it; WatchScanning says it doesn't Yes Yes
Date Yes Yes Yes
Our watches with it CADISEN C8244, CADISEN C8246 TI-7, BERNY AM339MS CADISEN C8175 None at the moment

Miyota is the movement division of Citizen, and both Miyota figures come from its own product pages. Seiko sells the NH35 to other brands through its Time Module business. We could not find an NH35 spec sheet from Seiko that we could read, so the NH35 figures come from independent references, named in the table where it matters.

What the beat rate changes

A mechanical watch's seconds hand moves in small steps, one for each swing of the balance wheel. At 21,600 vibrations an hour the 8215 and NH35 take six steps a second. At 28,800 the 9015 takes eight, so its seconds hand looks smoother as it sweeps round the dial. Miyota sells the 9015 in its Premium range and the 8215 in its Standard range.

Thickness: why the 9015 makes slimmer watches

The 9015 is 3.90 mm tall and the 8215 is 5.67 mm, so the 9015 is about 1.8 mm thinner. That difference reaches the case. The CADISEN C8175, on the 9015, is 11 mm thick. The CADISEN C8244, on the 8215, is 13 mm. If you want an automatic dress watch that fits under a shirt cuff, the 9015 is the movement to look for.

Hacking: setting the time to the second

"Hacking" means the seconds hand stops when you pull the crown out fully, so you can start the watch in time with your phone or a radio time signal.

The 9015 and the NH35 both hack. The 8215 is less clear. Miyota's own page lists a "stop second device" for it, but the WatchScanning guide to the 8215 says it does not hack, and that the seconds hand keeps running when you pull the crown. We will check our own C8244 and C8246 samples and update this guide. Until then, if setting the time to the second matters to you, choose the 9015.

Accuracy: what the tolerances mean

Miyota rates the 8215 at −20 to +40 seconds a day and the 9015 at −10 to +30. Sellers quote the same −20 to +40 for the NH35. These are tolerances: a new watch should land somewhere inside the range, and the range is all the maker promises.

"Posture difference" is how much the rate changes when the watch lies in different positions: dial up, crown down and so on. Miyota gives under 50 seconds for the 8215 and under 30 for the 9015, so the 9015 should behave more evenly through a day of wear.

WatchScanning says the 8215 and NH35 leave the factory with little or no fine adjustment. A watchmaker can regulate one, and WatchScanning says an NH35 can often be brought to within a few seconds a day. Every one of them will drift more than a quartz watch, which typically keeps to within about 20 seconds a month. If accuracy comes first, buy quartz.

Winding, noise and power reserve

All three wind themselves as you move and can be wound by hand at the crown. Each runs for about 41 to 42 hours once fully wound, which is roughly a day and a half off the wrist. If yours stops overnight, wind the crown 20 to 30 turns and set the time.

The 8215 winds in one direction only, and WatchScanning says its rotor is often audible when you move your wrist. That is normal for the movement and not a fault.

Which should you buy?

  • For an everyday automatic: the 8215. It is a simple movement, in production since 1977 according to the Grail Watch reference. The CADISEN C8244 is rated 10 bar at £115, and the C8246 TI-7 adds a titanium case and sapphire at £145. BERNY also uses it in the AM339MS dive watch.
  • For a slim dress automatic: the 9015. Ours is in the CADISEN C8175, 11 mm thick.
  • If you want hacking at 8215 money: look at an NH35 watch. We don't sell one yet.

You can see every self-winding and hand-wound watch we stock in Automatic & Mechanical Watches.

Questions

Does the Miyota 8215 hack?

Miyota's product page lists a stop-second device, but the WatchScanning guide says the 8215's seconds hand keeps running when you pull the crown. We will confirm on our own samples. The Miyota 9015 and Seiko NH35 both hack.

Is the Miyota 9015 worth paying more for than the 8215?

Yes, if you care about a smoother seconds hand, a thinner case or setting the time to the second. The 9015 beats at 28,800 vph against 21,600, is 3.90 mm tall against 5.67 mm, and has a tighter rated accuracy of −10 to +30 seconds a day. If you mainly want a tough everyday automatic, the 8215 does the job for less.

How long does a Miyota or NH35 automatic run off the wrist?

About 42 hours for the Miyota 8215 and 9015 and about 41 hours for the Seiko NH35, which is a day and a half or so. After that it stops; a few turns of the crown start it again.

How accurate is a Miyota 8215?

Miyota rates it at −20 to +40 seconds a day. Most run inside that range, and a watchmaker can regulate one to run closer.

Can I wind these movements by hand?

Yes. All three wind by hand at the crown as well as automatically as you wear them.

Sources

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