Miyota 9039: specs, accuracy and what hacking means (with the 9015 and NH38 compared)
Miyota 9039 specs from Miyota’s own data: 24 jewels, 28,800 per hour, 42 hours, hacking and hand-winding. Accuracy range, plus the 9015 and NH38 compared.
Miyota 9039: specs, accuracy and what hacking means (with the 9015 and NH38 compared)
What Miyota’s own spec sheet says about the 9039, what hacking and hand-winding mean in plain words, and how the published figures compare with the 9015 and the Seiko NH38.
The Miyota 9039 is an automatic movement from Miyota. Miyota lists 24 jewels, 28,800 vibrations per hour, about 42 hours of running time, hacking seconds and hand-winding, and a published accuracy range of -10 to +30 seconds per day for the calibre.
Disclosure: we are Vannin Watches, and the Vannin Field Watch, coming soon, uses the Miyota 9039. This page gives Miyota’s published specification for the calibre, not a test result of ours.
Below you will find the specification table, how the 9039 differs from the 9015 and 90S5, what hacking and hand-winding mean in plain words, what the accuracy range does and does not tell you, and a comparison with the Seiko NH38.
What is the Miyota 9039 movement?
The Miyota 9039 is an automatic movement: it winds itself from the motion of your wrist, and you can also wind it by hand. It is mechanical, so it needs no battery. Miyota files it under “Premium Automatic”, which is Miyota’s own category label, not a ranking.
Miyota is part of the Citizen group.
An automatic mechanical movement stores energy in a mainspring and uses a rotor that swings with your arm to wind it, so it needs no battery. Miyota lists this one as Cal. 9039, and it is the automatic Miyota 9039 that appears in the specification table below.
The 9039, the 9015 and the 90S5 share a base and differ in a few details. The section after the table sets those out.
Miyota 9039 specifications
These are the figures Miyota publishes for the 9039: 11 1/2 ligne, 26.00 mm diameter, 3.90 mm height, 24 jewels, 28,800 vibrations per hour and about 42 hours of running time. The table gives them as Miyota states them, with a plain-words column.
Miyota’s category label for the 9039 is “Premium Automatic”. Three notes on reading the table:
3.90 mm is the height of the movement alone, not the thickness of a watch. Case thickness depends on the case, dial and hands as well. Vibration frequency is counted per hour, so “bph”, “vph” and “per hour” all mean vibrations (beats) per hour. 28,800 per hour is 8 beats a second, shown in the diagram below. A ligne is a traditional unit of movement size; 11 1/2 ligne is 26.00 mm across on Miyota’s sheet.
Miyota publishes a specification sheet, a technical drawing, an instruction manual and a parts list for the 9039. They are linked from Miyota’s Cal. 9039 page, and the figures above also appear on the 9039 specification sheet (PDF).
Source: Miyota product page and specification sheet for Cal. 9039, checked 9 October 2026. Miyota’s instruction manual says specifications might change without prior notice.
| Specification | Miyota’s published figure | In plain words |
|---|---|---|
| Size | 11 1/2 ligne; 26.00 mm diameter | Miyota’s size class; 26.00 mm across on the spec sheet |
| Movement height | 3.90 mm | The movement alone; not the thickness of a watch |
| Jewels | 24 | The jewel bearings Miyota lists |
| Vibration frequency | 28,800 per hour | 4 Hz, or 8 beats a second |
| Running time | Approximately 42 hours | Running time as Miyota states it; not a promise for any one watch |
| Accuracy | -10 to +30 sec/day | Miyota’s daily-rate range; not a promise for any one watch |
| Posture difference | Under 30 sec | The permitted spread between positions |
| Functions | Stop second device; automatic and hand winding | Hacking seconds; self-winding and hand-winding |
Miyota 9039 vs 9015 vs 90S5: what is actually different?
On Miyota’s figures the 9039, 9015 and 90S5 share size, height, jewels, beat rate, running time and accuracy range. Miyota’s 9-series has several variants, and Miyota’s own pages carry the full list. The differences we show here are the pinion height and the 90S5’s open-heart window.
A common mix-up is to treat the 9039 as the thinner movement of the two. On Miyota’s movement list (PDF) it is not: the 9039, 9015 and 90S5 are all 3.90 mm high. That is also what each calibre’s own page says.
The list does show one dimension that differs. It gives each calibre a pinion height, which relates to how the hands are fitted: 1.75 mm for the 9039, against 2.10 mm for the 9015 and 90S5. Miyota’s specification sheets add that hand clearance depends on the glass, the case structure and the length of the hand, so we draw no conclusion about case thickness.
Miyota’s pages for each calibre carry its full details and variants: see Miyota’s 9015 page and Miyota’s 90S5 page. The 90S5 is the open-heart version, with a small window that shows the mechanical motion. If you are comparing the Miyota 90S5 vs 9039, the pinion height and that window are the differences we show here.
What about the 9019 automatic movement?
Miyota’s movement list also shows a Cal. 9019, with the same 3.90 mm height and 1.75 mm pinion height as the 9039. Miyota’s own 9019 page says the product is discontinued, so we leave it at that and give no further figures.
What is hacking on a watch? Hacking and hand-winding explained
Hacking, or hacking seconds, means the seconds hand stops while you set the time, so you can restart it at an exact reference. It is also called a stop-second function; Miyota’s name for it on the 9039 is “stop second device”. Here it means the seconds hand, not smartwatch security.
What is watch hacking, in practice? A feature, not a measure of accuracy. A hackable watch is simply one that has it, and in a hacking vs non hacking watch comparison the difference is whether the seconds hand can be held still while you set the time. WatchScanning describes watch movement hacking the same way for the 9015, and Miyota lists a stop-second function for the 9039.
Hacking seconds in four steps
Start to set the time. On a hacking watch the seconds hand stops as you do. Set the hours and minutes against your reference, such as a time signal. Hold the setting until your reference reaches the exact moment. Finish setting, and the seconds hand starts again from that moment.
These steps are general; the way you reach each one depends on the watch, so use the instructions for yours. Not every movement hacks, so check the specification. The 9039 and 9015 list a stop-second function, and so does the Seiko NH38, so hacking does not separate them.
Hand-winding
Hand-winding means you can wind the mainspring yourself by turning the crown, as well as letting the rotor wind it from wrist movement. Miyota lists the 9039 as “Automatic and hand winding”, so it is hand-windable.
It lets you start a stopped watch or top it up without waiting for wrist movement. We do not give winding instructions for any one watch on this page; for the Field Watch, our watch care guidance covers winding.
Why they matter, and when they do not
Neither feature changes the published accuracy range. Hacking is a convenience for setting the time; hand-winding is for starting or topping up. If you never set the time to the second, you may never notice either.
Miyota 9039 accuracy: what -10 to +30 seconds per day really means
Miyota publishes -10 to +30 seconds per day for the 9039. That is the daily rate Miyota specifies for the movement under its test conditions: a tolerance for the calibre, not a promise, prediction or measurement for any individual watch.
Daily rate is the number of seconds a watch gains or loses in 24 hours. The range is not centred on zero: it allows up to 30 seconds fast but only 10 seconds slow. Miyota also lists a posture difference of under 30 seconds, which is the permitted spread between rates in different positions.
For scale, as arithmetic only: held at the slow edge for 30 days, -10 seconds per day adds up to 5 minutes slow, and at the fast edge, +30 seconds per day adds up to 15 minutes fast. A rate does not sit at an edge, so this shows the size of the range, not what a watch does.
Miyota’s specification sheet says rate is checked in set positions, within 10 to 60 minutes of full winding. TMI’s NH38 sheet, quoted below, gives its own conditions, including 23 ± 2 °C. A real rate depends on more than a sheet can say: Rotate Watch Kits lists position, temperature, magnetic fields and regulation, and WatchScanning says regulation by a watchmaker is a separate step from the factory range.
The 9015 and 90S5 carry the same published range. The Seiko NH38’s published range is wider: -20 to +40 seconds per day on its specification sheet.
If a watch seems to run outside the range, contact the brand or retailer you bought it from.
Miyota 9039 vs Seiko NH38: a specification comparison
On published specifications the 9039 and 9015 run at 28,800 per hour against the NH38’s 21,600, are listed at 3.90 mm against 5.32 mm, and have a narrower published accuracy range. All three list a stop-second function and hand-winding. Table 2 gives every figure side by side.
Miyota figures are from Miyota’s product pages and the 9039 specification sheet. NH38 figures are from the NH38A specification sheet (PDF), technical guide (PDF) and catalogue (PDF) of TMI (Time Module), the Seiko Group company that sells the NH-series movements. Beats per second is beats per hour divided by 3,600. Checked October 2026.
8 against 6 beats a second, shown in the beats diagram earlier: at 28,800 per hour the seconds hand moves in smaller steps, eight a second. The NH35 is the NH38’s sibling in the same series; TMI’s catalogue gives both 5.32 mm, 21,600 per hour and 24 jewels. Anyone comparing the Miyota 9015 vs NH35 will therefore find the same gaps in beat rate and height. Worth a look if you want a series with several variants: TMI’s catalogue lists NH3-series versions that include a GMT hand and open-heart windows. The NH38 is a Seiko Group calibre and the 9039 is a Miyota calibre. Does Seiko use Miyota movements, or the reverse? No source we read says, so we make no claim either way.
| Specification | Miyota 9039 | Miyota 9015 | Seiko NH38 |
|---|---|---|---|
| Maker group | Miyota (Citizen group) | Miyota (Citizen group) | Seiko Group (sold as TMI) |
| Size | 11 1/2 ligne; 26.00 mm | 11 1/2 ligne; 26.00 mm | 12 ligne; 27.40 mm |
| Movement height | 3.90 mm | 3.90 mm | 5.32 mm |
| Jewels | 24 | 24 | 24 |
| Vibration frequency | 28,800 per hour | 28,800 per hour | 21,600 per hour |
| Beats per second | 8 | 8 | 6 |
| Running time | Approximately 42 hours | Approximately 42 hours | More than 41 hours |
| Hacking | Yes (stop second device) | Yes (stop second device) | Yes (stop second device) |
| Hand-winding | Yes | Yes | Yes |
| Published accuracy | -10 to +30 sec/day | -10 to +30 sec/day | -20 to +40 sec/day |
And the Sellita SW200?
The Sellita SW200 is another movement readers compare. We have not tabulated it because we have not checked Sellita’s own datasheet, so use that for its figures.
Miyota 8215 vs NH35, briefly
The 8215 is a different Miyota calibre. Miyota’s movement list gives it 21,600 vibrations per hour and a 5.67 mm height, so on those two figures it sits nearer the NH35, at 5.32 mm and 21,600, than the 9039 does. We say nothing here about its accuracy or hacking.
Is the Miyota 9039 a good movement? Servicing and availability
Miyota documents the 9039 well, with published figures for hacking, hand-winding, beat rate and an accuracy tolerance. Whether it suits you depends on what you value, and no specification says how one watch will behave. Miyota publishes no lifespan or service interval that we found.
What is sourced: Miyota publishes a specification sheet, drawing, manual and parts list for the 9039, its published tolerance is -10 to +30 seconds per day, and its movement height is 3.90 mm. Nothing we found covers servicing cost or parts availability, so we make no claim on either.
Buyers weigh movements differently, and some will prefer another maker’s calibre; that is a matter of preference, not a sourced finding. A published tolerance is a range, not a rating, and any independent watchmaker’s willingness to service a movement is theirs to confirm. For the movements independent microbrand watches use, see our roundup of British microbrand watches.
How long will a Miyota movement last? That depends on use and servicing, and Miyota gives no figure.
What this means for the Vannin Field Watch
The Vannin Field Watch uses the Miyota 9039 automatic. Its product page lists hacking seconds, hand-winding, a 42-hour power reserve, 28,800 BPH and 24 jewels, which match Miyota’s published figures on this page. At 28,800 BPH the movement beats eight times a second. Hacking lets the time be set against a reference, and hand-winding lets the watch be started or topped up by hand. Miyota specifies approximately 42 hours of running time. The accuracy range on this page is Miyota’s specification for the movement, not a statement about any individual Field Watch. The Field Watch is coming soon, and you can register your interest. For the dial, case and strap, see its product page.
See the Vannin Field Watch collection and register your interest on a colourway page. If you are new to the category, read what a field watch is. For how we came to this movement, read our Journal entry, why we chose the Miyota 9039 for our first watch, or why we chose a field watch for our first model.
Miyota 9039 FAQ
What is the Miyota 9039 movement? The Miyota 9039 is an automatic movement from Miyota, classed by Miyota as “Premium Automatic”. It is 11 1/2 ligne, 26.00 mm across and 3.90 mm high, with 24 jewels, 28,800 vibrations per hour and approximately 42 hours of running time. It has a stop-second function and can be hand-wound.
How accurate is the Miyota 9039? Miyota publishes -10 to +30 seconds per day for the 9039, the same range as the 9015 and 90S5. It is the maker’s tolerance for the movement under test conditions, not a promise for any one watch. Position, temperature, magnetic exposure and regulation all affect a real rate, so the range cannot predict how a particular watch will run.
What is the difference between the Miyota 9039, 9015 and 90S5? Miyota publishes the same size, height, jewels, beat rate, running time and accuracy range for all three. The 90S5 is the open-heart version, with a small window on the dial. All three are 3.90 mm high; Miyota’s movement list gives the 9039 a pinion height of 1.75 mm against 2.10 mm for the 9015 and 90S5. The 9-series has further variants, which Miyota’s own pages list.
Is the Miyota 9039 a good movement? Miyota documents the 9039 well: it publishes a specification sheet, drawing, manual and parts list, with figures for hacking, hand-winding, beat rate and a -10 to +30 seconds per day tolerance. Whether it is good for you depends on what you value. Miyota publishes no lifespan or service interval that we found, and no specification says how one watch will behave.
Is the Miyota 9039 better than the Seiko NH38? Specifications alone do not rank them, because they differ. Miyota publishes 28,800 per hour, 3.90 mm and -10 to +30 seconds per day for the 9039; TMI publishes 21,600 per hour, 5.32 mm and -20 to +40 for the NH38. Both hack and hand-wind. The NH35 shares the NH38’s height, beat rate and jewel count.
Are Miyota movements good? Miyota is a movement maker that publishes figures for the 9-series, so there is something to judge it on. Are Miyota automatic movements good? That depends on what you value, and some buyers will prefer another maker’s calibre; that is preference, not a sourced finding. A published tolerance is a range, not a rating.
What is hacking on a watch? Hacking means the seconds hand stops while you set the time, so you can restart it at a reference. So what does hacking mean in watches? It is also called hacking seconds or a stop-second function. Miyota’s term is “stop second device”. The 9039, 9015 and NH38 all have it. It is a convenience for setting the time, not a measure of accuracy.
Sources
Figures for the Miyota calibres come from Miyota’s own pages and PDFs. Figures for the Seiko NH38 come from the specification sheet, technical guide and catalogue published by TMI. Rotate Watch Kits and WatchScanning are cited for the factors behind a daily rate and for what hacking does. Browse more articles.
Miyota’s Cal. 9039 page; 9039 specification sheet (PDF); Miyota’s 9015 page; Miyota’s 90S5 page; Miyota movement list (PDF); TMI NH38A specification sheet (PDF); TMI NH3-series technical guide (PDF); TMI 2026-27 movement catalogue (PDF)
Prices and specifications checked October 2026. Tell us if something has changed.