What Does Hacking Mean on a Watch?

Two words appear on nearly every automatic watch listing and are almost never explained: hacking and hand-winding. They are separate features, they are frequently confused with one another, and between them they account for most of the difference in how two otherwise identical watches feel to live with.

Neither has anything to do with accuracy, durability or quality. Both are about the few moments a week when you actually interact with the watch.

Hacking: the seconds hand stops

When you pull the crown out to the time-setting position on a hacking watch, the seconds hand stops dead and the entire movement freezes. Push the crown back in and it starts again from exactly where it was.

The mechanism is a small lever — the stop-seconds or stop-second device — that swings into contact with the balance wheel when the crown is pulled and gently brakes it. With the balance stopped, the escapement cannot advance, so nothing in the watch moves. It is a designed, benign function, not a strain on anything.

Why anyone cares

Because it is the only way to set a mechanical watch to the second. Without hacking, the seconds hand keeps sweeping while you set the hands, so the best you can do is get the minute hand roughly right and accept being somewhere within half a minute of correct.

With hacking, the procedure is exact: stop the watch, set the hands to the next whole minute, wait for a reference clock to reach it, and push the crown in. The watch starts precisely synchronized. Our setting guide covers the full order, including the date-change window it is genuinely important to avoid.

There is a second, less obvious benefit: hacking makes it possible to measure your watch’s accuracy properly. You cannot tell whether a watch gains four seconds a day if you could only set it to within thirty. Our accuracy guide depends on it entirely.

Hand-winding: the crown winds the mainspring

A separate feature that often ships alongside hacking. On a hand-winding automatic, the crown in its neutral position winds the mainspring directly, exactly as it would on a manual watch.

Without it, an automatic can only be wound by rotor movement — which means the only way to start a stopped watch is to shake it or wear it until enough energy accumulates. That works, and it is a genuinely irritating way to start a watch.

With it, you unscrew the crown if it screws down, turn it clockwise 20 to 30 times, and the watch starts with real power in it. That matters more than it sounds, because a watch started by shaking begins near the weak end of its power reserve, where timekeeping is worst. Our winding guide covers the technique.

You still cannot overwind it

Worth repeating because it is the most persistent myth in the category. An automatic mainspring is attached to the barrel wall through a slipping bridle — a clutch that lets the spring slip once it is full. Neither the rotor, nor a winder, nor your hand at the crown can force in more energy than the spring will hold. Wind until the resistance goes smooth and stop; nothing breaks. Our power reserve guide explains what happens at the other end.

Which calibers have them

Nearly all modern automatics worth buying have both, which is a recent state of affairs.

• Seiko 4R35 / 4R36 — both, on Seiko’s published specification: automatic with hand winding, 24 jewels, 21,600 vibrations per hour, roughly 41 hours of power reserve. The NH35 and NH36 sold to other brands share the design and therefore the features.
• Miyota 9015 — both. Miyota publishes a stop-second device and automatic plus hand winding among the caliber’s functions, alongside 28,800 vibrations per hour and about 42 hours of reserve.
• Orient F6922 — both, and this is the reason the Mako II superseded the original Mako in every recommendation. The earlier caliber did neither.
• Older and very cheap calibers — frequently neither. Seiko’s own 7S26, used for years in the SKX line, famously did not hack or hand-wind.

Where a maker publishes nothing, our product spec tables print “Not published” on the hacking and hand-winding rows rather than assuming. A listing that does not mention either is usually a listing for a watch that has neither.

How much should either affect your buying decision?

Honestly: not much, at modern prices, because almost everything has both.

Where it does matter is at the extreme budget end and in the second-hand market. If you are considering a watch under about $80, or an older reference, check for both features specifically — the absence of hand-winding in particular is a daily annoyance that no other specification compensates for.

And treat the absence of both as a signal rather than a fault. A movement without hacking or hand-winding in 2026 is a movement built to the oldest and cheapest available design, which usually says something about the rest of the watch too. Our guide to choosing an automatic watch puts this among the movement checks rather than at the top of the list, because size and fit matter more — but it belongs on the list.

One practical warning

A hacked watch has its crown pulled out, which means the crown seal is open. On a watch with a screw-down crown that also means the crown is unscrewed.

Nothing is being damaged mechanically, but the watch is not water resistant in that state, and an unscrewed crown is the single most common cause of water ingress in otherwise healthy watches. Set the time, push the crown home, and screw it back down before you put the watch on. Our water resistance guide covers what a rating actually means once the crown is properly seated — and what happens when it is not.