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Truths About Automatic Watch Movements

5 Truths About Automatic Watch Movements

If a machine is “automatic,” we naturally assume it needs little to no human involvement to function. And while that assumption isn’t necessarily wrong, it’s also not entirely true when referring to wristwatches.

The three main types of watches are mechanical, automatic, and quartz. All of the functions in a quartz watch work via power supplied by a battery. In mechanical and automatic watches, the tension in the coiled mainspring delivers that power. A mechanical watch needs to be manually wound in order to coil the mainspring, whereas, in an automatic timepiece, the kinetic energy produced by the wearer does the winding.

After a Bumpy Start, Self-Winding Takes Off

Automatic movements got their start in the 1770s when Swiss clockmaker Abraham-Louis Perrelet developed a self-winding mechanism for pocket watches. The idea worked on a hinge system so that whenever you opened the watch to check the time, the hinge would pull on the movement and tighten the mainspring. 

Unfortunately, the idea didn’t catch on very well. The mechanism proved to be overly complex and costly. In addition, a person pulling out their watch occasionally to look at the time didn’t provide enough tightening to keep the mechanism wound.

Fast-forward to WWI, where a pilot or soldier often had no free hand to retrieve their pocket watch whenever necessary. To solve this problem, watchmakers created a wearable timepiece that would allow a person to get all the information they needed in a single glance to the wrist. 

It was then that British watchmaker John Harwood decided to pick up where Perrelet left off and take another stab at creating a workable self-winding watch movement. In 1922, while observing a couple of kids playing on a see-saw, Harwood developed the idea for the automatic bumper movement. The mechanism used a weighted metal plate that partially rotated along a 270° arc. As the plate bounced back and forth off the bumpers at either side of the arc, it would pull the mainspring coil and wind the watch. The kinetic energy generated by the wearer’s motion powered the metal plate.

Harwood patented his mechanism in 1924 and later worked with Swiss watchmaker Fortis to mass-produce the timepiece. At the 1926 international watch fair in Basel, Switzerland, the company presented the Harwood Automatic as the world’s first wristwatch with an automatic movement. A short time later, in 1931, Rolex further developed the concept by introducing the 360°-winding rotor, dubbed the Oyster Perpetual.

5 Truths About Automatic Watch MovementsEven as automatic watches dominate the market, there’s a lot that people don’t know about them. We asked our watch repair experts to share some basics about automatic watches based on questions we get in our shop.  

Truth #1: Automatic Watch = Mechanical Watch

Automatic watches fall under the category of mechanical watches. This can get confusing because there are so many terms to describe watches, and mechanical watches often become associated with hand-wound or manually wound watches.

Mechanical watch is the umbrella term, and manually wound (hand-wound) and automatically wound (self-wound) watches both fall under this umbrella.  

The difference lies in the fact that automatic watches have a weighted rotor atop the back of the movement. You have probably seen it before in timepieces with transparent case backs. It looks like a half-circle piece of metal that spins on an axis with the motion of your wrist and arm.

Although automatic watches can be every bit as complicated as their manual counterparts and are created by master watchmakers, there are some other differences. For instance, automatic watches tend to be heavier and thicker than manual ones because of the added rotor. Also, since automatics are much more common than manuals, you will find many more style and design options with self-winding watches. 

Truth #2: Automatic Watches Never Have to Be Wound via the Crown 

This is the beauty of automatic watches. We recommend that you swing your automatic watch gently from side to side about 10 times before you start wearing it. This kickstarts the motion instead of using the crown wind. Normal movement after that should be enough to keep your watch in motion.  

Even though it’s not necessary, some people like to hand-wind their automatic watches regularly to maintain that personal connection with their watch. 

Truth #3: You Can Overwind Your Watch

Thankfully, this doesn’t happen via the rotor. But it is possible to manually crank the crown too much and overwind your automatic watch. This is more likely to happen with older or cheaper watches. This is because in the old days, the mainsprings of a watch were anchored to the walls of the watch. With this construction, overwinding via the crown could damage the mechanical parts inside of the watch. Nowadays, the mainspring is not anchored in a way that it could compromise the inner workings of the watch if overwound. 

Fortunately, the mechanism of the self-winding watch, the rotor, has always been immune from this. The rotor cannot spin enough to create the force necessary to compromise the mechanical parts.  

Truth #4: An Automatic Needs Regular Servicing

Automatic watches seem so self-sufficient that people can forget to get them serviced. Every mechanical watch needs regular servicing. Period. Whether that’s every 2-3 years or at longer intervals, taking your timepiece to a qualified watch repair person who will clean out any accumulated dust and debris and properly lubricate the movement is essential. Allowing parts to wear out will not only affect the accuracy of your watch but may cause more significant issues down the road.

The timing of your service and where you go really depends on your brand. For example, Rolex wants their customers to get their timepieces serviced only at official Rolex jewelers or service centers every ten years. On the other hand, if you’re looking to save some time and money in maintaining your vintage Day-Date Presidential, consider seeking out a top-notch third-party Rolex repair shop and taking it in before the requisite ten years have passed.

Truth #5: Automatic Watches Don’t Have to Be Super Expensive

While mechanical and automatic timepieces are synonymous with luxury, craftsmanship, and accuracy, they do not all have the price tag to prove it. If you want to keep your budget under $1000, look no further than Tissot, Seiko, and Hamilton. Some popular standouts in this price range include the Hamilton Khaki Field, the Tissot PRX Powermatic 80, and the Seiko Prospex Alpinist.

Want to go even cheaper? The Orient Bambino and Orient Mako II are great options that can be had for less than $300.  

Of course, if you’re aiming to impress, you certainly have more expensive options, such as the popular Vacheron Constantin Overseas, Omega Planet Ocean 600M, IWC Schaffhausen’s Portugieser Chronograph, and the new Rolex Cosmograph Daytona.

Overall, automatic watches represent Swiss engineering at its finest and are worthwhile investments if you want the beauty of a classic mechanical paired with modern convenience.


When we hear the term “automatic” associated with machines, we instinctively think of devices requiring minimal human intervention. However, the world of wristwatches challenges this assumption, where automatic timepieces, alongside their mechanical and quartz counterparts, embody a fascinating blend of innovation and tradition. In this exploration, we delve into the history, mechanics, and truths surrounding automatic watches, shedding light on their evolution and essential characteristics.
5 Automatic Watch Facts