Watch Case: What It Is, Its Functions, and How to Measure It

The watch case is the structural element that encloses and protects the movement of the timepiece, while also defining its aesthetics, proportions, and stylistic identity. It is not simply an external casing, but a technical component designed to ensure resistance, waterproofness, and durability over time.

Understanding what a watch case is , what functions it performs, how to correctly measure it, and more, allows you to better appreciate the construction quality of a timepiece and make informed choices, both during the purchase phase and in the case of maintenance or technical interventions.

What is the watch case?

A watch case is the structure that houses and protects the caliber, dial, and crystal . From a construction standpoint, it represents the supporting frame of the entire timepiece. When we talk about the case of a wristwatch, we're referring to a component made of high-strength materials (such as steel, titanium, gold, platinum, or ceramic) designed to withstand impacts, dust, humidity, and temperature variations.

In contemporary watchmaking, the case serves more than just a protective function : it determines the character of the model, influencing its size, ergonomics, and presence on the wrist. Round, tonneau, or square-cased watches express different styles and traditions.

Wristwatch case: what functions does it have?

The wristwatch case It performs several essential functions , which go far beyond simply protecting the movement. First, it acts as a barrier against shocks, dust, humidity, and temperature variations , preserving the caliber's precision and reliability. Second, it contributes significantly to water resistance , thanks to the integration of gaskets and locking systems that seal the most sensitive points. From an aesthetic point of view, the case also defines the proportions, ergonomics, and stylistic identity of the timepiece .

Wristwatch case: what elements is it made of?

From a construction point of view, the case of a watch is made up of several elements that work in synergy :

• Case middle (central body) : This is the supporting structure of the case. It houses the movement and integrates the lugs for the strap, as well as the housings for the crown and pushers. It is the part that determines the shape, thickness, and overall resistance of the watch;

• Glass or crystal : protects the dial and ensures readability. It can be made of sapphire, mineral, or plexiglass, materials chosen for their transparency, scratch resistance, and structural strength;

• Bezel : ring that secures the crystal to the case, contributing to protection and watertightness. In addition to its technical function, it can play an important aesthetic role, with smooth, satin finishes, or those embellished with precious materials;

• Case back : closes the back of the case and protects the movement. It can be snap-on, screw-down, or screw-down, and sometimes transparent to show the caliber. It is a fundamental element for ensuring water resistance and access to internal components during maintenance;

• Crown and pushers : These interact with the movement, allowing you to set the time, date, and additional functions. Their integration into the case requires special care to maintain water resistance.

These components together form a compact, sealed structure , designed to ensure robustness, precision, and durability. In luxury watches —like those in the Pisa 1940 selection —the quality of the surface finishes (polishing, satin-finishing, chamfering) further enhances the case, transforming it not only into a technical element but also a distinctive "signature."

How do you measure a watch case?

Watch case size is one of the most important factors when choosing a timepiece. Its dimensions affect comfort, proportions, and aesthetic appeal on the wrist.

To measure a watch case , the main consideration is the diameter, measured in millimeters from one side of the case to the other , excluding the crown and pushers . This is the most commonly cited measurement in technical specifications. Other relevant values ​​include:

• Thickness (overall height);

• Lug to lug (distance between the lugs);

• Lug width (for strap).

A diameter between 36 and 40 mm is generally associated with elegant models, while sizes above 40 mm characterize sports or professional watches. Knowing how to measure a watch case allows you to choose proportions that suit your wrist and your desired style.

How to open a watch case?

Opening a watch case varies depending on the type of case back and requires appropriate tools to avoid scratches and compromising the seal. Here's an overview:

• Snap-on caseback : it is embedded in the case middle and opens by levering up the notch on the edge. Care must be taken to avoid deforming the caseback or damaging the gasket;

• Screw-down case back : it screws onto the case and is opened by unscrewing it using a special tool that hooks into the grooves on the case back. This is a typical solution for sports models because it helps ensure a better seal;

• Screw-on caseback : secured with micro perimeter screws. Opening is achieved by removing them with precision screwdrivers, taking care not to strip the heads and maintaining uniform tightening when closing.

When it comes to high-end watches, it's best to avoid improvised interventions: even a "simple" opening can affect the finish and water resistance.

How to close a watch case?

Closing the case is just as delicate as opening it . After working on the movement or battery, the case back must be replaced correctly to restore watertightness. In snap-on models, the closing is done using a watchmaker's press that distributes the force evenly. In screw-on case backs, the thread must be tightened with controlled precision , avoiding both under- and over-tightening.

Improper sealing can compromise water and dust protection, making it essential to have the appliance serviced by a specialized laboratory.

Polishing a watch case: how to do it correctly

Polishing a watch case is a process aimed at restoring its original aesthetic appearance, eliminating micro-scratches and signs of wear. However, it is a process that must be performed with great care . Each case has specific finishes (polished, satin, brushed), and improper polishing can alter the geometry, blunt the edges, or reduce the value of the timepiece.

For this reason, watch cases are polished using professional machinery and specialized techniques , respecting the original design of the respective Maison. In the luxury sector, preserving proportions and surfaces is as essential as maintaining proper mechanical function.

Case opening, closing, and polishing: trust the Pisa 1940 workshops

The watch case, therefore, is the structural heart of the timepiece: it protects the movement, defines its aesthetics, and ensures reliability over time. Operations such as opening, closing, or polishing require technical precision and professional tools .

For any case work (from maintenance to cleaning to restoration), it's best to rely on specialized workshops like Pisa 1940, where qualified watchmakers operate according to the standards of the most prestigious watchmakers. Relying on expert hands is the only sure way to preserve the integrity, value, and beauty of your timepiece.