Understanding Watch Specifications and Why it is Important for Timepiece Collectors

Understanding Watch Specifications
Understanding Watch Specifications

In nearly all of our articles here at Rubber B, and across the horological (watchmaking) world, writers refer to a small set of terms that help potential investors and watch collectors understand the differences between these magnificent creations. Many of these features are hard to distinguish unless you are a watch repair person, designer, or extreme collector. We depend on these features to understand, not only the capabilities of the timepiece, but also to find which timepiece best fits your own personal tastes and needs.

One person might want to have a timepiece that can withstand a particular waterproofness depth because they are an avid yachtsman, fisherman, swimmer or diver. Another person might want something that can provide excellent strength and resilience and be built with powerful cases, scratch resistance and a caliber that can get banged around without skipping a beat. Travelers and airline pilots might want a GMT feature to give them multiple time zones at one time. And so on….

The features of each watch and company that produces these gems are distinct as well. Rolex has been at the forefront of making tool watches that are built for a specific purpose such as Diving, or Racecar Driving, or Exploration, just to name a few. Other companies like Audemars Piguet and Patek Philippe may be more focused on designing the ultimate luxury timepiece. The specifications can help you understand the slight differences between these brands, or watches within the brands. In this article I will work to expose some of this jargon and help you understand why it might matter to you as a watch-o-phile or collector.

Understanding Watch SpecificationsIn-House Movement vs Imported Movement

Developing an entirely in-house movement is a sign that a watch manufacturer has taken a huge leap into the realm of horological independence. Having total control of every design element means that there are no excuses and that the level of excellence to build that timepiece must rise to meet a higher echelon of purity that only a few companies can achieve. Even Rolex outsourced their calibers for years before bringing the end to end manufacturing of their own calibers in house.

A timepiece that is fully built in-house may take months to assemble, test and certify, whereas a timepiece that has an imported movement produced by one of the mass production caliber providers could be assembled in a matter of days or weeks. Being able to manufacture your own caliber gives you more ability to test and improve the movement over time.

Rolex, for example, recently was able to optimize their power reserve dramatically by improving the Chronergy escapement and barrel architecture. Over the years Rolex made slight improvements, such as using paramagnetic alloys to reduce sensitivity to magnetic fields, temperature variations, and to shocks. If a watch company just takes a movement from one of the caliber manufacturers such as ETA, there is a feeling that there is less less craftsmanship, heritage or exclusivity even though ETA has been making excellent calibers since 1793.

There is no guarantee that a company that builds their own caliber in-house will make a superior product. However, watch collectors seem to feel that those that do, such as Rolex, can utilize the best materials and improve the overall quality. The fight over in-house movements has caused companies like the Swatch Group to acquire ETA, and Citizen to buy Miyota. This also spurred more companies to develop their own in-house movement.

Understanding Jewels and Total # of Components

Automatic and hand wound watch calibers require little manufactured synthetic rubies to reduce or eliminate friction. Jewels can provide long lasting efficiency within a timepiece because with lubrication the jewel can act as a pivot point with other watch components made out of steel or other materials.

Most fine watches have at least 17 jewels in them. However, the competition to create complex calibers utilizing more jewels has driven the count much higher in modern calibers. For example, the new Rolex caliber 3230 comes with 31 jewels found in the Rolex Submariner, as does the Panerai OP XVIII which appears in its highly complex Rattrapante timepiece. Although early timepieces may have contained actual rubies in the design, these naturally occurring gems were not a common occurrence and would have driven the price of the timepiece too high. Today jewels can be custom designed to fit a specific size and purpose within the caliber it supports.

Just as jewel count can be a measuring stick of excellent workmanship, the number of components can also indicate the complexity of the timepiece itself. Just as it takes much longer to put together a 1,000 piece puzzle than a 500 piece puzzle, so does assembling a timepiece with a much higher amount of pieces. The P.2002/E caliber from Panerai is a pretty complex caliber with 328 components and a large array of functions that include the date, month, small seconds, equation of time and power reserve indicator. That is a significant amount of pieces compared to its P.9010 model that has a mere 200 components.

Water Resistance

Most modern timepieces are certified with a specific level of water resistance. It is common to see a timepiece with at least a 50 meter resistance which should cover most casual swimming and diving adventures. However, true dive watches are often built with 300 meter support or more. This is the case for fine dive watches like the Rolex Submariner and the Panerai Submersible. This depth is certainly more than enough for even pro divers.

Yet, Rolex has created two additional timepieces to extend the limits of waterproofness. The Sea-Dweller supports a depth of 1220 meters, and the Rolex Deepsea supports an incredible 3,900 meters. These timepieces would support extreme diving expeditions such as diving into the Mariana Trench.

The Case Size

Watches today are becoming much larger than they were in years past. Rolex timepieces often would have the 36 or 40mm case, but have been growing in recent years to 41 and 44mm. Panerai has many 47mm timepieces.

Case size is one of the features that customers look at when selecting their timepiece. Some people want a small thin case, whereas others want to feel a larger and thicker case on their wrist. The size of the case can also determine the visibility of the dial. Larger cases can support larger hour markers, bigger hands, and more luminescent paint to keep the timepiece illuminated in the darkness.

Power Reserve

The power reserve is something that many people look at. They don’t want to be inconvenienced with having to wind their timepiece each day or have to reset the watch time when they put the timepiece on in the morning. Most automatic watches will wind when you wear it, so you don’t ever need to wind the timepiece. However, if you remove the watch, it has to continue working without the support of your normal body’s movement to help wind it. If you take off a business watch on Friday night, it would be helpful if the timepiece can have enough reserve power to last until you have to go back to work on Monday morning.

However, power reserve is something that varies widely among timepieces. Until recently Rolex only supported about 42 hours of power reserve. Recently, due to its newly enhanced caliber, it supports 72 hours on most models. Panerai has some models that have some extreme power reserves, even up to 8 and 10 days of power reserve.

Sapphire Crystal

The scratch resistant glass on the timepiece is a big feature that watch owners demand. Sapphire is the most expensive and preferred watch glass to other materials. It is clear, durable and has greater scratch protection than mineral glass or plexiglass. Sapphire is difficult to polish and could shatter under extreme circumstances. However, with the anti-reflective coating, the crystal seems to disappear. It resists scratches and tends to look new for many years even with active wear.

Almost all fine timepieces made with a pricetag over $1000 will come with Sapphire glass. It is less common to find $400 timepieces with Sapphire, but there are a few that do.


Watch movements beat at rates based on the design. One of the most common frequencies is the 28,800 vph model. This is a high frequency which keeps the time stable. It is less common to find slower frequency models in today’s environment. For example, early calibers by Rolex back in the 1960’s would often beat at 18,000 bph. Rolex made improvements in later decades with calibers that supported 19,800 bph. Today it is common to see 21600 vph and 28,800 vph. However there are many calibers with other frequencies in production.

Watch Bands

Watch bands probably took a back seat to most of the above features found inside a timepiece. However, many watch manufacturers have taken great pride in coming up with enhancements for their bracelets. Rolex has made multiple bracelet styles but then made improvements such as the glidelock and extension systems to make it easier for people to adjust their metal bands.

This is where Rubber B picked up the baton and ran with it. Rubber B has extended the horological boundaries of what is possible with Rubber watch bands that can create a motionless fit to the case (Blocked Engineering) but also support multiple closures including the original deployant clasp, tang buckles, and even Velcro straps. Rubber B has made recent enhancements with coming up with a new way to manufacture the texture of the band itself in order to replicate the look and feel of real leather like alligator hide or fabric like Kevlar. These designs are 100% vulcanized rubber and vegan friendly.

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