Hamilton · Hamilton H-10

Hamilton Khaki Field Auto, Khaki Navy Scuba and Jazzmaster power reserve: inside the H-10

The Hamilton Khaki Field Auto, Khaki Navy Scuba Auto, Jazzmaster Viewmatic and Khaki Aviation Pilot Auto all run on the H-10. Fully wound, it runs for 80 hours, a little over three days.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the Hamilton H-10

The H-10 is Hamilton's standard three-hand automatic, with or without a date. If a current Hamilton says "Auto" on the dial and has no chronograph, GMT hand or day display, it almost certainly has an H-10 inside. These are the models people search for most.

Outside Hamilton, the same base movement shows up as Tissot's Powermatic 80 (in the PRX, Gentleman and Seastar) and in Mido and Certina automatics under their own names.

Specs at a glance

History and where it came from

For decades, a Khaki Field or Jazzmaster automatic ran on the ETA 2824-2, the Swiss industry's default three-hand movement, with a reserve of about 38 hours. In the early 2010s the Swatch Group, which owns both Hamilton and ETA, rolled out a re-engineered version of that movement across its mid-priced brands. Tissot called it Powermatic 80. Hamilton called its version the H-10.

Under the name, the H-10 is the ETA C07.611. It keeps the 2824's basic layout, but three changes matter. The balance was slowed from 28,800 to 21,600 vibrations per hour. The mainspring is longer and thinner. And the gear train was reworked to lose less energy. Monochrome's coverage of the Khaki Aviation Converter describes it as an upgraded 2824-2 with a 3 Hz frequency, 25 jewels and an upgraded gear train. The result more than doubled the reserve, to 80 hours.

Two details set the H-10 apart from some Tissot siblings. It keeps a conventional metal escapement with 25 jewels rather than the synthetic escapement in the 23-jewel Powermatic 80. And current H-10s use a Nivachron balance spring, which Hamilton promotes for its resistance to magnetism and temperature changes. Hamilton also finishes it differently by collection: American Classic and Jazzmaster models get snailed and pearled decoration, while aviation models get plainer surfaces and a rotor with aviation-style cut-outs.

Accuracy in the real world

Hamilton doesn't publish an accuracy spec for the H-10, and none of the Khaki Field or Jazzmaster models is chronometer certified. That leaves owner reports. They're generally good: single-digit daily rates are the norm, and figures like +6 or +8 seconds a day, or an owner averaging between -2 and +4, come up regularly for the Khaki Field Auto.

There's variation between individual watches, as with any mass-produced movement. One Khaki Navy Scuba might run +2 while another sits at +10. If yours is well outside that range and suddenly started gaining a lot, magnetism is the usual suspect, though the Nivachron spring makes that less likely than on older 2824-based Hamiltons.

The slower 3 Hz beat is sometimes blamed for weaker accuracy. In theory a slower balance is more easily disturbed by knocks. In daily wear owners rarely report it as a problem. What you'll notice is the seconds hand: it sweeps six steps a second rather than eight, which is visible only if you look for it.

Reliability and servicing

The H-10 has a solid reputation. Complaints about Khaki Field and Scuba watches are more often about bracelets, crowns and dial glare than about the movement itself, and there's no known systemic fault.

Servicing is more complicated. Swatch Group restricts C07 parts to its own network and to certified watchmakers. Hamilton's official service may return your watch with a replacement movement rather than overhauling the original, which is efficient but not what everyone wants. Some independent watchmakers will service an H-10 if they can source parts; others decline. It's worth asking locally before you buy if that matters to you.

Because the C07 shares the 2824's footprint, watchmakers can fall back on a 2824 or Sellita SW200-1 if a movement were ever beyond repair, though you'd lose the 80-hour reserve. In practice, many owners wear the watch until accuracy or reserve drops noticeably rather than servicing on a fixed schedule.

Quirks worth knowing

• Rotor noise. Like the 2824, the rotor can be heard and felt spinning when you shake the watch. It's normal.
• Slow to fill. An 80-hour spring has a lot to wind. From a full stop, 30 to 40 crown turns gets it going with a useful reserve.
• Date changes. On dated models such as the Khaki Field Auto and Scuba 40, avoid setting the date late in the evening while the date wheel is engaged. Here's why.
• Not every "Auto" is an H-10. Older Khaki Field and Jazzmaster references, and the 38mm and 42mm Intra-Matic, use ETA movements with around 38 to 42 hours of reserve. Check the reference before assuming 80 hours.
• Different names, same base. If you're comparing a Khaki Field Auto with a Tissot PRX, the movement isn't the difference. Case, bracelet and water resistance are.

How it compares

• ETA 2824-2. Found in older Hamiltons. 4 Hz with a smoother sweep and easier independent servicing, but about 38 hours of reserve. The H-10 trades beat rate for more than double the reserve.
• Powermatic 80. Near-identical in spec and behaviour. Some Tissot versions use a synthetic escapement or a silicon balance spring; the H-10 sticks with metal and Nivachron.
• H-40 and H-30. Hamilton's day-date versions of the same family, with the same 80 hours, used in the Khaki Field King and Khaki Field Day Date.
• H-50. The hand-wound sibling in the Khaki Field Mechanical, also 80 hours.
• Seiko 4R35. The movement in many similarly priced Seiko 5 and Presage watches. Cheaper to replace, but about half the reserve and a looser factory tolerance.

Living with the 80-hour reserve

This is the H-10's best feature. Take a Khaki Field Auto off at 6pm on Friday and, if it was fully wound, it's still running at 2am on Tuesday. A whole weekend of wearing something else won't stop it, which a 38-hour 2824 Hamilton can't promise. It's why a Khaki Field and a Jazzmaster share a rotation so easily.

The catch is "fully wound". An automatic only charges while it's worn, and a desk day adds less than you'd think. If you only wore your Khaki Navy Scuba for an evening before putting it back in the drawer, it may have far less than 80 hours in it. Watch Winder counts down the reserve for each watch you own from when you took it off, and reminds you before it stops. To check a particular weekend, try the "Will my watch stop?" calculator.

Verdict

The H-10 is a big reason the Khaki Field Auto and Jazzmaster Viewmatic are such easy recommendations. It's reliable, usually accurate to within single-digit seconds a day, resists magnetism, and its 80-hour reserve makes owning more than one watch much less of a chore. The trade-offs are a slower 3 Hz sweep and a service network that prefers swapping movements to overhauling them. For a daily field, dive or dress watch, neither is a dealbreaker.

FAQ

How long does a Hamilton Khaki Field Auto run off the wrist?

About 80 hours when fully wound, a little over three days. It will usually survive a weekend in the drawer, but only if it was well wound when you took it off.

Does the Hamilton Khaki Field Auto hack?

Yes. The H-10 stops the seconds hand when you pull the crown out to set the time, and it can also be wound by hand.

How accurate is the Hamilton Khaki Field Auto?

Hamilton doesn't publish an official tolerance for the H-10. Owners commonly report single-digit seconds per day, and many see within a few seconds a day.

What movement is in the Hamilton Khaki Navy Scuba Auto?

Current Khaki Navy Scuba Auto models use the H-10 automatic with an 80-hour reserve and a Nivachron balance spring. The 40mm has a date; the 43mm version does not.

Is the Hamilton H-10 the same as the Tissot Powermatic 80?

They share the ETA C07 base, 3 Hz beat and 80-hour reserve. The H-10 uses the 25-jewel metal escapement and a Nivachron balance spring, while some Powermatic 80 versions use a synthetic escapement or a silicon spring.

Does the Jazzmaster Viewmatic have an ETA movement?

Yes. The Jazzmaster Viewmatic Auto uses the H-10, which is Hamilton's name for the ETA C07.611, a Swatch Group movement developed from the ETA 2824-2.

Why did my Hamilton Khaki Field stop overnight?

Almost always because it wasn't wound enough. A few hours of light wear adds only part of the 80-hour reserve, so give it 30 to 40 turns of the crown before you put it on after a stop.

Sources

• Hamilton: Khaki Field Auto H70455133
• Hamilton: Jazzmaster Viewmatic Auto H32755131
• Hamilton: Khaki Navy Scuba Auto H82305931
• Monochrome: Hamilton Khaki Aviation Converter collection
• aBlogtoWatch: 36mm Hamilton Khaki Aviation Pilot Auto review

Watches we've reviewed with the Hamilton H-10

• Hamilton American Classic Intra-Matic Auto review
• Hamilton Jazzmaster Auto review (Viewmatic, Performer and Thinline)
• Hamilton Khaki Field Auto review
• Hamilton Khaki Field Murph review
• Hamilton Khaki Navy Scuba Auto review
• Hamilton Ventura Elvis80 Skeleton Auto review

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 20 hours of wear fills the Hamilton H-10. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 80 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

All Hamilton movements · Other 80-hour movements

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the Hamilton H-10: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.