For watches, a watch case is an essential parts of a watch.Many newcomers to the watch industry are curious about what is the case of a watch. What is the role of a watch case? A watch case is the outer shell of the watch movement and watch face which protects the watch mechanism from the outside world and keeps everything running smoothly.

    In this blog, we’ll give you a detailed overview of the watch case parts, meaning, shape, size, and everything else related to the case.

Table of Contents

Watch case parts

    Watch case parts include many small parts (case body, bezel, watch case back, lugwatch crystal, plastic cover, crown). The lug and bezel are part body and come out of the grinder inside the case body along with the case body. However, watch crystal, plastic cover, and watch case back are all small accessories that are produced separately. In terms of function, the case serves as a housing for the movement, and the case protects the watch movement and the watch dial from damage. The case is connected to the crown, which is used to adjust the time, calendar, dual time, GMT and chronograph functions. In terms of aesthetics, the watch case is a key aspect of the watch design. The shape, color, and material of the watch case determine the overall look and feel of the watch. Overall, the watch case plays a crucial role in determining the overall quality and aesthetic appeal of a watch.

what is the case of a watch

Watch Crystal

    A watch crystal is the transparent glass material that covers the watch face. Watch crystal type include watch sapphire crystal, Mineral crystal and acrylic crystal. Their function is to protect the watch from the external environment and to provide a polished look at your watch.

Watch Lug

   Watch lug is where the strap, band or bracelet is attached to the case. The strap is attached to the case through the spring bar to form a unit.

Watch bezel

      The bezel, which holds the crystal glass in place, is typically made of stainless steel, aluminum, or ceramic. The bezel has various functions such as GMT, Dive, Countdown, Count up, Tachymeter, Compass, etc. Watch bezel can remain still, rotate in one direction, or rotate in both directions.

Watch case back

      A watch case back is of the rear cover of the case. It protects the internal part of the watch. And when you need to change the battery or repair a watch, the first thing is to remove the case back to the watch. Most of case backs are made of 304 or 316L stainless steel. But some mechanical watches will have a sapphire crystal glass back, through which you can see the mechanical movement at work.

   The watch case back type is watch case back press, watch case back screws, Screw-off back and push-down. The customer can customize the case back watch with their own design or documents. Watchessy provides custom watch case cover service and helps their guest to add series number on the back of watches.

watch case back

Watch plastic rear cover

      The inner watch cover is used to link the watch case body to the movement and the movements are fixed into the watch case. The watch dial foot fixes the dial to the movement. The watch hand holder fixes the hands to the movement. In this way, the inner cover connects the face, hands, movement, and case, forming a complete unit.
     The material of the inner cover of the watch is usually plastic. However, some customers use brass inner cover to enhance the quality or increase the weight of the watch.

Watch rear cover

Watch Crown

      In the watch industry, sometimes the crown is also considered being part of the watch case. Watch crown is made of stainless steel or copper.The crown is used to adjust the time and calendar as well as the chronograph function.

Watch case material

    When it comes to case materials, we have many choices. Next we will give an introduction to some common case materials to help you choose some suitable case materials.

Stainless steel case

    Stainless steel material has good corrosion resistance and wear resistance, and the price is moderate, very suitable for making a watch case.There are different stainless steel (304, 316L, 904L). For example, many dive watches use 316L stainless steel. Rolex watch cases are made of 904L stainless steel.


     Titanium is known for their high strength, lightweight and resistance to corrosion, making titanium ideally suited to the watchmaking industry. In addition, titanium is harder and more difficult to polish than stainless steel, making titanium cases more costly than stainless steel. Titanium is 30% stronger than stainless steel, and a titanium case of the same size is 45% lighter than a stainless steel case. So wearing a titanium watch is more comfortable.

Bronze watch case

       Brass and bronze cases have become increasingly popular in the past few years. Brass comprises 66% copper and 34% zinc. Bronze comprises copper and 10% tin. Brass cases are softer and heavier than stainless steel materials and are less resistant to corrosion. Over time, the metal in bronze reacts with oxygen or sweat, etc. to produce a copper green color. Therefore, many bronze cases also have stainless steel case back.

Aluminum watch case

      Compared to stainless steel cases, aluminum cases are softer and lighter than stainless steel. But the scratches of the aluminum case are not as obvious as those of stainless steel. So the case of Apple Watch has both stainless steel material and aluminum case. If you want a watch that is lighter and relatively inexpensive, the aluminum watch is a good choice.

 Alloy watch case

    Usually, when we say the alloy case, we mean zinc alloy. Compared with stainless steel cases, zinc alloy is cheaper, lighter, less corrosion resistant and easy enough. Only low-end watch cases are made of alloy. Alloy watches are used to make some promotional gifts and so on.

Ceramic watch case

     Ceramic is a new material for the watchmaking industry, but ceramic watches are hard, resistant to wear and corrosion. Compared to stainless steel cases, they are lighter in mass and harder to scratch. Watch Manufacturers can color ceramic watches in various ways, enhancing their aesthetic appeal. Ceramic watches have a disadvantage of being susceptible to catastrophic damage if they experience a violent impact, resulting in a cracked or shattered case.


Wood watch

    The Wooden watches are becoming more and more popular as the concept of environmental protection is gaining popularity. Wooden watches are made of eco-friendly materials such as maple, sandalwood, teak, or materials that can be reborn. Wooden watches are lighter, more comfortable and durable to wear.

       Carbon fiber watches are watches made from materials such as carbon fiber or forged carbon. These materials are known for their superior strength, durability and the fact that they are lightweight. However, carbon brazed dimension also has the disadvantage of being easily scratched as well as not resistant to wear and tear. Polishing can solve scratches on stainless steel watches, but it cannot solve scratches on carbon fiber.

Plastic watch

   Plastic is one of the most common materials used in the manufacture of watch cases. Plastic watches are inexpensive, but the Minimum order quantity is high, similar to alloy watches. It is suitable for the low-end market, such as for promotional gifts.

Case diameter watch

     Case diameter watch is one of the most important considerations when buying a watch or starting a watch brand. The case size in watches is the diameter of the case, excluding the crown. Children’s watches are 22-30mm in diameter, women’s watches are 26-38mm, and men watches are between 38 and 46mm. Of course, if you prefer a smaller watch size, you can also choose a 26mm watch. If your preference is for a larger watch, you can choose a 48 or 50mm watch.

    Wearing a correct and size of the watch will make people feel comfortable. To give you a more intuitive feel for watch sizes, we offer a watch size chart for your reference.

watch case size

How to measure watch case size mm

    If you wear an inappropriately sized watch, you will look awkward as a whole. So it is very important to choose to wear the right size of a watch. How to measure the case size? Case size is the size of the diameter of the case, to be measured from the outer edge of the widest part of the watch, excluding the crown. If it is a square watch, the description size should be the length and width of the case.

how to measure watch case size in mm

Watch case shape

     Watch case shape represents the design style of the watch and can express the designer’s philosophy. Generally speaking, there are 8 common case shapes:









   Among them, round and rectangular, square are more common. The main reason most of them are round is that it is easier to see the time in a round case and the watch hand moves around in a circle.

watch case shape

Conclusion-what is the case on a watch

    With this blog, you have a comprehensive understanding of what is a case on a watch. If you want to custom watch case or create your own brand, watchessy as a watch case manufacturer can customize a case (case size, shape) according to your requirements and budget. We also have different shapes and sizes of women and men to watch cases for our guests to choose.


Custom watch case

     After understanding what is a watch case, then you can custom own wath case.

    First, choose the watch case material.
  Based on your watch function and budget, choose the perfect watch case material. Now in our watch factory, Alloy, plastic,316L or 904L stainless steel, Ceramic, Titanium steel and Carbon fiber case are available. If your watch is as promotional gift, then the alloy or plastic watch case is a good option. If your watch is for diving, Then Titanium or stainless steel case are better.

   Second, choose the watch case shape
   Most of the case of watch shape is round. But the square, Tank, Oval, Octagon case is also available. You can choose the watch case shape based on your watch style.

    Third, determine the watch case size
    Based on your target customer gender, then you can determine the watch case size. The kid watch case size is less than 30mm. The women watch case size is less than 38mm.38mm and 40mm are unisex. Most of the men’s watch size is over 40mm.

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