A bezel is an upper ring of the watch that surrounds the crystal. On a watch, some snap or screw on, some are fixed, and some can rotate in one direction or the other. All watches have some sort of bezel, whether it is a thin ring around the glass or a piece of ceramic containing a ladder.
Overall, there are many varieties of bezels and they are often associated with particular complications and functions. However, they are rarely decorative and each is designed for a specific use. In this detailed guide, you will learn the different functions of the most common types of watch bezels.
In addition, we will show you how to use them correctly and how you can even integrate them into your daily life according to your activities.
Types of bezel scales
Depending on the number of different functions of a watch, there are many different types of bezels and bezel scales. Some bezel scales are located on top of the main bezel and can rotate in either unidirectional or bidirectional directions. Diver's watches sometimes have a bezel that is internally controlled by an additional crown. This feature helps prevent accidental shocks, which can lead to miscalculations.
However, some scales are not on the top of the case but rather on the outer edge of the dial. Instead, they open the main bezel of the watch to allow the use of more case materials with a smooth finish. Nevertheless, it always performs the same calculations regardless of where the scale is located.
Single fluted bezel
Not all glasses fulfill a technical function, with a scale or numbers. Rather, they show the design of the watch with historical influences. These watches usually only show the time or date and have the classic metal bezel, which is smooth. In some cases, this bezel is also fluted, thus paying homage to the watchmaking of the period. This is the time when the fluted part was used as a handle to remove from the watch. The size of these bezels can vary from a thin strip of metal on the case surrounding the dial to a thicker piece of metal surrounding the glass. In addition to being plain or fluted, some brands take advantage of this space and add diamonds for some models.
Tachometer
One of the most common scales seen on the outer ring of the dial or on the bezel is the tachometer or pocket tachometer. What is a tachometer? It is a scale on a fixed, non-rotating bezel that calculates units per hour for chronograph watches.
When you look at the scale, you see that it starts around the 7-second mark at 1000 and ends at the 12-hour mark with 60, which means that it can measure times from 7 to 60 seconds.
This type of scale can be used to measure speed or distance, but some measurements may require more mathematical equations than others.
Pulsometer
The pulsometer is one of the rarest scales found on a watch. It is usually found on a watch of medieval design and worn by doctors. This type of addition dates back to the 1920s when doctors needed to accurately measure a patient's pulse. Like the tachymeter scale, which measures units per hour, the pulsometer measures heart rate in one minute. The scales are calibrated from 15 to 30 beats around the dial, starting at 200 around the 5-second mark. Doctors would start the chronograph and count the beats until their watch was calibrated, then stop the chronograph. When they stopped, they could read the heart rate in beats per minute based on the alignment of the second's hand on the pulse scale.
Rangefinder
The tachymeter is also similar to the rangefinder, which can also be confused with the former because of their similar names! This type of scale is less common and is used to measure the distance between a visible event and a sound event. The best way to describe this type of scale is to look at a thunderstorm. For example, you start the stopwatch when you see lightning and start it when you hear thunder. The stopwatch then moves to the top of the distance, usually measured in kilometers.
Decimeter / Decimal Bezel
Offered as a custom alternative to the tachometers on the Speedmasters, the decimal or decimeter bezel is a slightly rarer scale. Not to be confused with the unit of length of the same name, decimeters allow the user to translate time into decimal values. It is easily recognizable by the characteristic scale of 100, which is mainly used for scientific and industrial measurements. In combination with the chronograph, a time measurement can be easily converted to a decimal or percentage for use in longer calculations. For example, the 6 o'clock position indicates 50, which can be converted to 50% or 0.5 minutes. While some rounder time stamps are easy to convert proportionally to decimals, this tool makes the task relatively simple for more complex time readings.
GMT / Greenwich Mean Time
The GMT function stands for Greenwich Mean Time and is also known as UTC or Coordinated Universal Time.
Most watches with an added GMT complication will have a large rotating bezel on the outside of the glass with a 24-hour ring, just like the Rolex GMT Master II BLNR. Nevertheless, it is possible to have a GMT without the rotating bezel. In this case, the 24-hour ring will be placed around the flange between the indexes and the edge of the dial. The Grand Seiko GMT SBGJ001 has this type of 24-hour scale.
In both cases, the GMT hand goes around the dial, making one complete rotation over a 24-hour period. Watches with a rotating bezel sometimes feature two colours to highlight the hours of the day or night. A rotating bezel also makes it possible to use a third time zone if necessary.
Watches with an inner 24-hour ring will be read in the same way. The GMT hand aligns with the 24-hour scale, and then the minutes are read by the central minute hand.
Counting bezel
The bezel is usually found on a diver's watch to calculate the elapsed time. It has a scale from zero to 60 around the bezel, which is aligned with the minutes of the hour. The first 15 minutes are usually marked in one-minute increments, sometimes up to the first 20 minutes. After the end of the minutes, the rest of the bezel is marked in five-minute increments. This method is specially designed to avoid running out of air during a dive.
In addition, the bezel is unidirectional and rotates only counterclockwise. This means that if you bump the bezel while diving, you can only have less time and more air in your tank. To use this style of bezel, you place the zero mark, usually identified by a triangle and a large luminous dot, with the minute hand at the beginning of your dive. As time passes, you read off the elapsed time on the bezel, with the first 15 minutes being tracked individually.
Yacht-Timer
The Yacht-Timer is mainly used in boat races. Usually, along the outer edge of the bezel, there is a 10 to 1 stopwatch that extends over the upper 2/3 of the bezel. However, different brands create stopwatches of different styles.
In boat races, a horn signals the start of the countdown to the race time. The aim of the crew is to avoid crossing the starting line before the second signal starts the race. In general, stopwatches indicate the time remaining until the actual start of the race.
Slip rule
One of the most complicated and misunderstood bezel scales on a watch is the slide rule. This type of scale helps you to multiply and divide. This function was made popular by Breitling in the 1950s when they launched the Navitimer.
In the 1950s, this scale allowed pilots to calculate fuel consumption, speed, and distance and to include conversions from the metric to the standard system. Even today, pilots are still learning to use the slide rule; however, most people outside the profession do not know how to use the scale. Since Breitling understands that people generally do not know how to use this function, they have published a comprehensive user manual.
