What Are Watch Jewels: A Detailed Guide

Whether you are looking for a mechanical watch or an automatic timepiece, you have probably noticed that their movements have a set, particular number of jewels. This, of course, leads us to a very important question: just what are watch jewels and what do they do?

Watch jewels are very significant components of a watch movement. They are responsible for ensuring that a watch movement operates smoothly and efficiently. Indeed, the number of jewels a movement has can even affect its performance. 

If you are not familiar with what watch jewels are, and are wondering what they are for, let our article guide you on all of their functions and purposes. In addition, we will also give you an insight into what watch jewels are made of and how the number of jewels in a movement can have a direct effect on a watch’s performance. So if you ever wanted to have the question “what are watch jewels” answered for you, read on to find out more!

What Are Watch Jewels and What Are They For?

Watch jewels are essentially the building blocks that hold a watch movement together. Also referred to as jewel bearings, watch jewels are incorporated within different parts of the watch movement. Watch jewels ensure that the numerous components of the watch’s engine move smoothly and freely, without the metal parts damaging one another. 

For example, watch jewels are set on the wheel train of the movement in order to prevent friction, so it can run more smoothly. In particular, they are positioned on the axle of the wheel, which allows this component to move swiftly without the worry of creating friction, which would lead to wear and tear. Without watch jewels, the wheels of the movement would be more prone to metal wear. This would cause damage to the engine, which would consequentially result in an inaccurate display of time.

Most of the time, watch jewels cannot be seen as they are hidden alongside the watch movement, behind the caseback of timepieces. However, many high-end watches, such as the Grand Seiko Taisetsu SBGA415, offer exhibition-style casebacks. Made from metal and sapphire crystal, these transparent casebacks give you a glimpse of the watch jewels on the timepiece’s movement. 

Types of Watch Jewels

Watch jewels come in many different sizes. They are also set on various components of the watch movement for specific, corresponding purposes. Originally crafted from precious stones like diamonds, sapphires, rubies, and garnets, watch jewels in the modern era are now made from synthetic sapphires and rubies. This helps to reduce the cost of production, offering a more affordable way of crafting watch movements. 

Hole Jewels

Hole jewels are circular in shape and bear a hole in the center of them. Also referred to as pierced jewels, these are attached to the axles of the wheels and pivots of watch movements. They are also customized so that they can fit perfectly into the tiny, circular sections of the movement. 

Cap Jewels

Cap jewels come in a flat, circular shape. They are used to minimize the movement of the caliber’s balance staff. They serve almost the same purpose as hole jewels, but cap jewels differ in that they do not have holes in the middle. When used alongside hole jewels, these two types of watch jewels act as pivot bearings. 

Cap jewels usually have two springs at both ends too. This provides shock-resistant properties to the movement, which protects it in case you accidentally drop or hit your watch. 

Pallet Jewels 

Pallet jewels are rectangular jewels that are situated at both ends of the pallet fork. The pallet fork locks the escape wheel, allowing the balance wheel to swing in a fluid motion. Since the pallet fork moves in a continuous back-and-forth course, the pallet jewels help reduce the friction that is caused by this constant movement.

Roller Jewels

Roller jewels are constructed in a rectangular shape, but with a rounded and curved top. They are located inside the pallet fork. Roller jewels are utilized to link the escape wheel together with the pallets.

Watch Jewels: Are More Jewels Better?

Some folks believe that the number of watch jewels bears a direct effect on the performance of a timepiece. However, this is not exactly true. Instead, the number of watch jewels in a watch caliber actually only affects how many functions and complications it has. 

In short, the fewer watch jewels a movement has, the fewer functions it is equipped with. Conversely, more watch jewels mean that a watch caliber comes with more complications. To illustrate this, let us compare two famous watch movements which each come with a different number of watch jewels.

ETA 2824-2 movement

First, we have one of the most ubiquitous Swiss calibers, the ETA 2824-2 movement. This caliber is used by many remarkable Swiss watch brands, such as Tissot, Longines, TAG Heuer, and Tudor.  It is also known for being used by the German watch brand Junghans and the American watchmaker Hamilton. 

The ETA 2824-2 movement is fitted with 25 jewels. These jewels drive the movement’s relatively straightforward functions, which include the central hours, minutes, sweeping seconds hand, and a date feature at 3 o’clock. Indeed, since the ETA 2824-2 movement only has a limited number of watch jewels, it also comes with a commensurate number of complications. 

Rolex Caliber 4130

Compared to the ETA 2824-2 movement, the Rolex Caliber 4130 is equipped with an abundant number of jewels. The Rolex Caliber 4130 is designed exclusively for the brand’s chronograph timepieces, with one popular example being the Rolex Platinum Daytona. 

The Rolex Caliber 4130 is also much more complex, being held together by 44 jewels. Thanks to its greater number of jewels, this Rolex automatic movement offers a wider range of complications. These include hours, minutes, sweeping small seconds, central chronograph seconds, along with 30-minute and 12-hour chronograph counters. 

Final Thoughts

Having an insight into what are watch jewels is helpful in attaining a better understanding of our precious timepieces. Although it is quite technical, the watch jewel is one of the most important components of a watch, and one you should certainly know about. 

Having said that, it is also necessary to note that having fewer watch jewels does not necessarily mean that a watch movement performs more poorly compared to a caliber with more jewels. Instead, a movement with more watch jewels simply comprises a more complicated caliber with extra features.

Photo credits: webcasamiento, User 2427999, and Radoslaw Pietrzykowsk on Pixabay, Hamilton, and Rolex.

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