Tudor · Tudor MT5602

Tudor Black Bay and Pelagos FXD power reserve: inside the MT5602

The 41 mm Tudor Black Bay, the Black Bay Ceramic and the Pelagos FXD all run on Tudor's Manufacture Calibre MT5602, which lasts about 70 hours off the wrist. That's just under three days, enough to sit out a weekend and still be running on Monday morning.

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

Watches that use the MT5602

If you own a 41 mm Tudor Black Bay made since 2016, it almost certainly has an MT5602 or one of its close relatives inside. Tudor uses the same no-date, time-only calibre in the titanium Pelagos FXD, and a slightly larger twin, the MT5601, in the 43 mm Black Bay models. Master Chronometer versions carry a "-U" suffix; they're the same movement with extra testing.

Two things can trip you up. The 39 mm Black Bay 58 uses the smaller MT5402 or MT5400, not this one. And Black Bays with a date window, or a GMT hand, use other members of the family such as the MT5652.

Specs at a glance

History and where it came from

The Black Bay launched in 2012 with a modified ETA 2824 inside, a sound movement with a 38-hour reserve and no chronometer certificate. Tudor's first in-house automatic appeared in the North Flag in 2015, and in 2016 the Black Bay got its own version: the MT5602, fitted to the 79230 series in black, blue and burgundy.

The upgrade was substantial. Monochrome's 2016 review lists the gains: COSC certification, a reserve that nearly doubled from 38 to 70 hours, a silicon balance spring for magnetic resistance, a variable-inertia balance adjusted by screws instead of a regulator arm, and a transversal bridge over the balance for shock resistance. The price rose only modestly, which is a big part of why the Black Bay became Tudor's defining watch.

Tudor calls it a "Manufacture" calibre rather than "in-house". It is made with Kenissi, a movement maker in which Tudor holds a stake alongside Chanel. The "MT" stands for "Manufacture Tudor".

In 2021 the Black Bay Ceramic introduced the MT5602-1U, Tudor's first movement certified by METAS as a Master Chronometer. In 2023 the regular Black Bay followed with the MT5602-U, along with a case that is 1.2 mm thinner. Monochrome notes that the -U movement is technically almost identical to the 2016 one; what changed is the testing, and "Master Chronometer" is engraved on the plate.

Accuracy in the real world

Every MT5602 is COSC-certified, which means the bare movement averages between -4 and +6 seconds a day in testing. Tudor then applies its own, tighter standard of -2/+4 seconds a day to the finished watch. Master Chronometer versions add METAS testing of the cased watch: 0/+5 seconds a day, at two temperatures, six positions and both a full and a one-third-wound mainspring, plus resistance to 15,000 gauss.

Owner reports on watch forums are mostly consistent with those numbers: many Black Bays run a couple of seconds a day fast and stay there. There are exceptions. A reader comment on Monochrome describes a Black Bay that ran poorly from new and was later found to be faulty, so if yours is well outside -2/+4 while under warranty, send it back rather than living with it.

The silicon hairspring matters more day to day than the certificate. A Black Bay that sits next to a laptop speaker or a magnetic bag clasp is far less likely to suddenly gain minutes a day than the old ETA version.

Reliability and servicing

The MT5602 has been in production for about a decade and there's no known systemic weak point. The design was built for a tool watch, with the full balance bridge specifically meant to cope with knocks.

• Warranty. Tudor gives a five-year guarantee on current watches, which covers most owners' first years with the watch.
• Brand service. Tudor's service network handles it, and that's the realistic route. Parts for Tudor's manufacture calibres aren't freely available to independents the way ETA and Sellita parts once were.
• Independents. Some qualified independents do service them, but fewer than for a 2824. As one Monochrome reader put it, a METAS-certified movement is in practice a job for Tudor, which can be slower and dearer.

The trade-off compared with the old ETA Black Bay is clear: better specs and certification, but a narrower choice of who can open it.

Quirks worth knowing

• Thickness. At 6.5 mm the movement is chunky, which is why the 2016 to 2023 Black Bay is 14.8 mm thick. The 2023 redesign got it to 13.6 mm, and the Black Bay 58 uses the thinner MT5402 to get to about 12 mm.
• No date. The MT5602 is a true no-date movement, so there's no phantom date position when you pull the crown.
• Takes a while to fill. A 70-hour mainspring needs a proper wind from empty. Give it a good number of crown turns rather than relying on the rotor over a quiet desk day.
• Solid casebacks. Apart from the 2021 Black Bay Ceramic, you can't see the movement. The rotor is openworked, but you'll only see it at a service.
• Suffixes. MT5602, MT5602-1U and MT5602-U are the same basic movement. The "U" means METAS Master Chronometer.

How it compares

• Rolex 3230: the Submariner No Date's movement also runs 70 hours at 4 Hz, with a Chronergy escapement and a tighter -2/+2 Superlative Chronometer rating. It costs a lot more.
• ETA 2824-2 / Sellita SW200-1: what powered the first Black Bay. Any watchmaker can service them, but 38 hours won't survive a weekend.
• Omega 8800: the Seamaster Diver 300M's Master Chronometer, with a co-axial escapement and 55 hours. Shorter reserve, more anti-magnetic engineering.
• Tudor MT5402: the Black Bay 58's smaller, thinner sibling with the same 70-hour, 4 Hz, COSC recipe.
• Oris Calibre 400: a five-day reserve and a 10-year warranty at a lower price, but not independently certified.

Living with the 70-hour reserve

Seventy hours is the useful kind of long. Take your Black Bay off at 6pm on Friday and, from a full wind, it's still running at about 4pm on Monday. A normal weekend in a drawer won't stop it, which the ETA-powered original couldn't manage.

The margin is thinner than it sounds, though. Take it off late on Friday after a light week, or leave it until Monday evening, and a Black Bay or Pelagos FXD can easily stop before you pick it up. If you rotate a dive watch with a dress watch, give the Black Bay a proper crown wind before you put it down. Watch Winder counts down this 70-hour reserve for each watch you own and reminds you before it stops. To check a specific gap, try the "Will my watch stop?" calculator.

Verdict

The MT5602 turned the Black Bay from a well-styled watch with an ETA inside into a genuine rival for far more expensive divers. You get 70 hours, a silicon hairspring, a free-sprung balance, chronometer certification and, in current versions, METAS testing. The costs are thickness in the older Black Bays and a servicing route that mostly runs through Tudor. For most owners that's a fair trade, and the five-year guarantee softens it further.

FAQ

How long does a Tudor Black Bay run off the wrist?

A fully wound 41 mm Black Bay with the MT5602 runs for about 70 hours, just under three days. If it wasn't fully wound when you took it off, it will stop sooner.

Does the Tudor Black Bay hack?

Yes. The MT5602 stops the seconds hand when you pull the crown out to set the time, and it can be wound by hand through the crown.

How accurate is the Tudor Black Bay?

The movement is COSC-certified and Tudor aims for -2/+4 seconds a day on the finished watch. Master Chronometer versions from 2023 on are also tested by METAS to 0/+5 seconds a day.

Does the Tudor Pelagos FXD use the same movement as the Black Bay?

Yes. The Pelagos FXD uses the COSC-certified MT5602, the same 70-hour, 4 Hz movement as the 2016 to 2023 Black Bay.

What is the difference between the MT5602 and the MT5602-U?

The MT5602-U is essentially the same movement, but each watch is also certified by METAS as a Master Chronometer, including 15,000-gauss magnetic resistance and a 0/+5 seconds a day tolerance.

Why did my Tudor Black Bay stop over the weekend?

It most likely wasn't fully wound. The 70-hour figure assumes a full mainspring, and a light week or desk days may leave it well short. Wind it by the crown before putting it away.

Is the Tudor MT5602 made by Rolex?

No. It's a Tudor Manufacture calibre produced with Kenissi, a movement maker Tudor part-owns. It isn't a Rolex movement, though Tudor and Rolex share an owner.

Sources

• Monochrome: What's new in the 2016 Tudor Heritage Black Bay 79230 with manufacture movement
• Monochrome: The entire Tudor Black Bay lineage, 2012 to 2024
• Monochrome: Tudor Black Bay Master Chronometer Monochrome 7941A1A0NU
• Caliber Corner: Tudor Caliber MT5602
• Tudor: Black Bay M7941A1A0RU-0001 product page (archived)

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 18 hours of wear fills the Tudor MT5602. 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 70 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 Tudor movements · Other 70-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 Tudor MT5602: 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.