Many owners of wrist chronometers, especially those who have encountered mechanics for the first time, often wonder what the professional and correct name is for that very “twist” located on the side of the case. In everyday life, this element is called differently: button, wheel, screw, but the technically correct name is crown. It is this small but critical unit that is responsible for starting the mechanism, setting the exact time and, in many models, for managing the calendar.
Understanding how it works crown, is necessary not only for general development, but also for the proper operation of an expensive accessory. Improper handling of this element can lead to damage to the mechanism, moisture getting inside the case, or stripping the threads. In this article we will analyze in detail the anatomy of this unit, consider its types and give recommendations for care so that your watch can serve for decades without failure.
It is important to note that the design can vary significantly depending on the brand and type of mechanism. If you are the owner of classic mechanical Longines or sports Casio, the principle of operation will be similar, but the nuances of operation may differ radically. Let's figure out what is hidden under this term.
Official terminology and anatomy of the node
Among professional watchmakers, the term “twist” is not used. The correct element name is crown (or crown in English). However, if we are talking about a complete set, then the head itself is only the upper, visible part of a more complex system. It is connected to an internal shaft, which passes through the body and interacts with the mechanism for winding the spring and moving the hands.
You can often hear this part called a “winding screw.” The name stuck because many waterproof models have a threaded head that screws into the body to seal. The internal part connecting the head to the mechanism is called shaft trim or just a shaft. It is this that transmits torque from your fingers to the watch gears.
Materials used also play a role in durability. Budget models often use plated brass, while premium ones Rolex or Omega 904L steel or even precious metals are used. The crown is often the weakest point in a watch's water resistance system, so special attention must be paid to its condition.
⚠️ Attention: Never try to forcefully pull out the head if it does not give in. In screw models, this will lead to thread breakage and loss of tightness.
Therefore, when you speak to a craftsman, use the term "crown" to ensure that you are understood correctly. This demonstrates your awareness and respect for the mechanism.
Types of fastening and principle of operation
There are two main types of crown mounting, and understanding the difference between them is critical for the owner. First type - extraction head. It is simply spring-loaded and can be removed with a slight movement of your finger. Such models usually have a low degree of water protection or do not have it at all. The fixation mechanism here is simple: the head is held in the body by spring pressure.
Second type - screw head. This is standard for dive watches and models with water resistance of 100 meters and above. Before changing the time or winding the watch, such a crown must first be unscrewed counterclockwise. Once the operation is complete, it screws back tightly, pressing the O-ring against the body and creating a reliable barrier to water.
The principle of operation also depends on the number of positions. In the classic version there are three:
- 🕰️ Zero position: the crown is pressed against the case, the watch is operating normally, and the spring can be wound (in mechanics).
- 📅 First position: light click, rotation changes the date or day of the week.
- ⏰ Second position: the second click, rotation moves the minute and hour hands.
In some complex mechanisms, such as Grand Seiko or chronographs, the number of positions may vary, and the logic of operation may be more confusing. Always check the instructions for your specific model before actively manipulating the head.
Functional purpose of the crown
The main function for which this part was invented is mechanism plant. In a mechanical watch, turning the crown clockwise (when it is in the zero position) winds the mainspring. This action accumulates energy, which is then spent on the operation of the balance and chassis. Without regular winding, mechanical watches will simply stop.
The second key function is time setting. By pulling out the crown, we disconnect the winding mechanism from the arrow transfer mechanism. This allows us to set the exact time, synchronizing with reference signals. In quartz watches such as Seiko or Citizen, pulling out the crown often also stops the second hand (hack mechanism function) for more precise setting.
If you have a mechanical watch with self-winding, do not be lazy to periodically wind it with the crown manually, especially if you do not wear it every day. This will lubricate the mechanism and prevent the oil from solidifying.
Third function - calendar management. In models with a date, day of the week or even month, the crown serves as a switch for these indicators.
⚠️ Attention: It is strictly forbidden to change the date on a mechanical watch between 21:00 and 03:00. At this time, the shift mechanism is already running, and a forced change may break the gear teeth.
Thus, the small “twist” serves as a remote control for the entire complex organism of your watch.
Problems with sealing and waterproofing
The issue of water resistance is directly related to the condition of the crown. As mentioned earlier, this particular node is the most vulnerable point. Inside the head there is one or more rubber o-rings (O-rings). Over time, rubber loses elasticity, dries out and cracks.
If you own a screw head, the "dry crown" rule is the gold standard for safety. This means that the crown can only be opened (unscrewed) when the watch is completely dry. If soapy water or bleach gets into the threads when unscrewing, it can lead to corrosion or leaching of the lubricant.
Regular leak testing is a must. Once every 1-2 years it is recommended to undergo maintenance, where a technician will replace the seals. Ignoring this rule may result in moisture penetrating while washing hands or in the rain and causing corrosion of the mechanism, which will cost expensive repairs.
| Head type | Water protection | Risk of moisture ingress | Recommended maintenance frequency |
|---|---|---|---|
| Exhaust | Low (30-50 m) | High | Once every 3-4 years |
| Screw | High (100-300+ m) | Medium (if used carefully) | Once every 2 years |
| Helium valve | Professional | Low (special design) | Once a year (for divers) |
Remember that the stated water resistance (for example, 5 ATM) is static pressure in the laboratory. In real life, when moving your hand in water, the pressure is dynamic and can be much higher.
Common faults and their causes
One of the most common problems is head failure inside the body. This happens when the lever spring breaks or slips out of place. In this case, the head dangles and is not fixed in the time adjustment positions. Repair requires opening the mechanism and replacing the fixing part.
Another common problem is too tight or, conversely, excessive play. Stiff movement often indicates thickening of the lubricant or dirt and dust getting into the head bore. If the head spins idle and does not wind the clock or move the hands, the shaft trib may be broken or the shift clutch may be worn out.
What to do if the head breaks off?
If the head breaks off from the shaft, do not try to pick the hole with a needle. You can push a piece of debris inside the mechanism, which will complicate repairs significantly. Carefully assemble all parts and take them to the service center.
There is also the problem of “jamming” of the screw thread. This often occurs due to oxidation of the metal or lack of lubrication on the threads. In such cases, the technician has to use special solvents and ultrasonic cleaning to free the mechanism.
It is important to monitor the condition of the head visually. If you notice scuffs, dents or discoloration of the metal, this may be a sign of the beginning of corrosion processes.
Instructions for proper use
In order for your “crank” to serve for a long time, you must follow simple but important operating rules. First of all, always keep this unit clean. Dirt, sand and lint from clothing tend to get into the gap between the head and the body, acting as an abrasive.
☑️Daily care of the crown
If you have a screw head, tighten it all the way, but without fanaticism. Excessive force may distort the O-ring or strip the threads, especially on soft gold or titanium models. The feeling of resistance is a signal to stop rotating.
When changing the time, try not to turn the hands counterclockwise if the instructions for your watch (for example, Miyota or ETA) does not explicitly allow this. Reverse rotation puts extra stress on the gear teeth.
⚠️ Attention: If the crown stops locking or falls out, do not shake the watch. Carefully place them face down and contact a service center as soon as possible.
Following these simple recommendations will extend the life of the mechanism and maintain its accuracy.
Repair and replacement: is it worth doing it yourself?
Replacing a factory head or its shaft is a jewelry job that requires special tools and experience. To remove the shaft, you need to find a point on the mechanism (usually a small recess next to the shaft), press it there with a thin pin and at the same time pull out the head. Trying to do this with improvised means (a needle, a knife) is almost guaranteed to lead to scratches on the mechanism or broken bridges.
Additionally, factory heads are not universal. They differ in the diameter of the mounting hole, shaft length, thread pitch and tip shape. Choose an analogue for a watch Tissot or Certina “by eye” is impossible. An exact match to the mechanism article number is required.
Replacing the head yourself is only possible if you have the exact part number and a special tool for installing it, otherwise the risk of damaging the mechanism is 90%.
The cost of replacement in the service consists of the price of the part itself and the work of the technician. For high-end brands, the original crown may cost a significant amount of money, but it is worth it to maintain the functionality and appearance of the watch.
Is it possible to swim with a watch if the head is retractable?
Strongly not recommended. Exhaust heads do not provide reliable protection against dynamic water pressure. Even if the watch says 50 meters, this is protection against splashes and rain, but not against swimming. Water will quickly penetrate through the gaps.
Why does the watch head become hot to the touch?
This is a rare but possible phenomenon. If the crown becomes hot, this may indicate serious friction within the movement (for example, a jammed shaft) or that the watch is in a high-temperature area. In the first case, the mechanism requires urgent lubrication and cleaning.
How often should head seals be lubricated?
Seals are lubricated only during service (every 2-3 years). You shouldn’t go there with oil yourself: you can use the wrong type of lubricant, which will corrode the rubber, or bring in dust, which will lead to depressurization.
What is “fool proof” in crowns?
In many modern mechanisms (for example, Swatch Group) there is reverse protection when setting the time. The hands only move clockwise. This prevents the calendar mechanism from breaking if the user accidentally turns it back.