From the Bench: The Truth about “Overwinding”

Watchmakers are often confronted with the same complaint, no matter where they work: someone is worried that they “overwound” their watch, and can it be fixed?

As a watchmaker, I hear this question a lot from both new and experienced watch collectors. But here’s the thing—for as many times as I’ve been asked about overwinding, I’ve almost never seen a watch that was actually overwound.

This may seem counterintuitive, since “overwound” is such a common term that even non-watch-people know it, but it’s true. Let’s look at the term and what people really mean when they talk about overwinding their watch.

Most often, when someone shows me an “overwound” watch, it’s perfectly fully-wound—just not running. This is the source of most confusion. We expect that as a watch is wound up, it will start to run. When someone winds their watch, and the crown gets tighter and tighter until it finally stops, it feels like something is wrong! It’s true, there is something wrong, just not with the winding.

Manually-wound watches have a hook on the barrel wall that catches a tongue on the end of the mainspring. This provides a solid and secure foundation for the spring, and won’t slip—so the mainspring will wind to its full tension and stop.

Automatic watches cannot be overwound; they have an infinitely-slipping mainspring. The barrel walls are lined with a special “braking grease” and the mainspring uses a sliding bridle to push against the walls, yet still be able to slip. This allows the automatic to keep winding the barrel forever, keeping the mechanism from binding up.

You can test this yourself! If you have a manually-wound watch, go ahead and wind it. At a certain point it will stop, and so should you. You can power through the stop, but you’ll just be breaking something in the winding or powertrain. This is overwinding. 

If a watch is wound so hard that the mainspring breaks, it will just easily wind forever and the watch will never run. If something else breaks in the winding train, it will either feel rough and skippy or the crown will just come out in your hand.

Again, this experiment doesn’t work on an automatic watch, since the mainspring will infinitely slip. But go ahead and try! You can wind an automatic watch until you get blisters on your fingers and nothing will break. If you listen closely, you can hear the mainspring slipping at full wind; it’s a slight “click” every few winds once the watch is fully-wound.

So the next time you’re worried about overwinding a watch, rest a bit easier. The watch will tell you when to stop if it’s manually wound (don’t overpower it!), and an automatic will slip forever. If you fully wind the watch and it still doesn’t run, don’t blame yourself or the mainspring—but it’s still probably time for a service. Send us a message and we'll get it back in tip top shape.