Case Back

The entire case back is screw into place using a specialized tool that catches each of these notches. Despite its seemingly simple design, it is a very effective means of achieving up to 5ATM water resistance.

The Screw Down case back, like the name suggests, is fastened to the case using at least 4 separate screws. This method provides up to 10ATMs water resistance.

What makes a watch water-resistant?

Several features make a watch water-resistant; the most important components are the gaskets (O-rings), which are usually made from rubber, nylon, or Teflon. They form watertight seals at the joints where the crystal, case back, and crown meet the watch case. If the watch is a chronograph, the chronograph pushers will also have gaskets. Watches cases are also lined with a sealant, applied in the form of a quick-hardening liquid that helps keep water out.

The thickness and material of the case also affect a watch’s water resistance; it must be sturdy enough to withstand pressure without caving in. Stainless steel or titanium are optimal materials for water resistance, and watches made from solid gold or have gold plating can be made water-resistant if they are sufficiently thick.

Screw-down case backs also contribute to a watch’s water resistance. Screw-down crowns, typically found in divers’ watches, help prevent water from getting into the case through the watch stem hole; screwing it down forms a seal similar to the lid on a jar.

Why aren’t watches ever labeled or advertised as “waterproof?”

“Waterproof” implies that the watch is impervious to water under all conditions, which is something that no watch manufacturer can claim. While you diver watches have incredible water resistance, under enough pressure, all watch cases will begin to leak. The term “waterproof” was discontinued in the 1960′s after several government organizations investigated the truthfulness and accuracy of product labeling and advertising.

When you see a watch’s water resistance, say 100 meters, or 330 feet, it means that under “still” conditions at depths no greater than 100 meters, the case should not leak. The movement of water over the case while swimming drastically changes how it affects the water-resistant seals – it alters the pressure while it’s moving through the water.

Levels of water resistance and practical applications

30 meters (100 feet): Can withstand splashes of water or rain. Not recommended for swimming or diving.
50 meters (165 feet): Can be worn while showering or swimming in shallow water.
100 meters (330 feet): Suitable for swimming and snorkeling.
150 meters (500 feet): Suitable for snorkeling.
200 meters (660 feet): Suitable for skin diving.

Diver’s 150 meters (500 feet) specified to meet ISO standards: Suitable for scuba diving.
Diver’s 200 meters (660 feet) specified to meet ISO standards: Suitable for scuba diving.

It is crucial to keep in mind that these tests are done in a laboratory, not in the ocean, and are done under still water conditions.

Is water resistance permanent?

Short answer, no. A watch’s water resistance will wear down over time through wear and year. The gaskets can become corroded or misshapen, and dented cases and loose crystals can ruin water-resistance. Preventative maintenance will ensure that your watch will last for years and years. After swimming or diving in salt water, immediately rinse the watch with fresh water to prevent salt buildup and corrosion of important water-resistant components. This goes the same with heavily chlorinated water, some perfumes and hairsprays, and other corrosive chemicals that can make their way into the watch’s seams and gaskets. If your watch is still wet, do not push any of the buttons or pull out the crown! This will likely lead to water getting inside the case and cause condensation to appear on the crystal.

What other factors affect water resistance?

Temperature. Drastic changes in temperature, particular with the water in which it’s submerged, can affect water resistance because heat and cold causes the metals to expand and contract. Opening the case back by yourself can ruin water resistance, which is why only a professional should work on your watch (also voids your warranty if you do it yourself). Have your watches inspected and worked on periodically by a watchmaker, and you will be golden.

Jewels in watch movements serve a very important function in keeping the timepiece operational. Because there are a lot of moving parts in a watch movement, including the balance wheel and palette fork, it puts a lot of stress and friction in the steel. Over time, it would wear down on the metal until it becomes too worn to work properly. The jewels are placed in strategic locations to serve as a buffer between moving parts, which reduces friction, as well as wear and tear. In general, the level of complications can be guaged by the number of jewels in the movement. Rubies are typically used because of their incredible durability; they rate 9 on the Mohs scale of hardness (10 being the highest, which is the hardness of diamonds).

Someone once asked me about the purpose of oil-filled watches. This was my answer:

Many diver watches, exclusively quartz watches, use silicon oil in order to improve case durability and water resistance. These oils are used because liquids are relatively incompressible; that is, they are resistant to high environmental pressure. Because high pressure and lower temperatures reduce the overall volume of oil, it creates a vacuum (lower temperatures cause silicon oil to contract; the same amount of oil takes up less space when cooled), a flexible membrane or moveable piston in the case back is used to compensate for the difference. The oil also improves legibility of the watch face by mitigating light refraction and preventing condensation (fogging).

It’s a very interesting innovation for diver watches. A possible drawback, however, is the fact that no watch is completely waterproof. A little bit of water will still flow into the case and take up the space left behind by the “compressed” oil at lower depths so that after repeated submersions, bubbles may eventually form. When that happens, the watch would require repair or maintainace to refill the case or possibly replace the flexible membrane in the case back.

Many of Stuhrling Original’s watches include rich texturization on the dial that makes the entire timepiece come alive. We achieve this using vintage German machinery that hydraulically stamps the specifically engineered pattern on to the dial plates, a process that can take up to thirty continuous compressions, depending on the depth of the grooves. The result is an amazing finish and shine.

Mother-of-Pearl

The women’s models in Stuhrling’s collection often include genuine mother-of-pearl inlays, a material we import from Australia. Their irridescent light refraction gives these petite timepieces a bolder, more noticeable presence on the wrist, especially when they are accented with Swarovski crystals or genuine diamonds! When it comes to using these inlays, many times the mother-of-pearl must be custom-cut in order to fit into the overall style and design of the watch: a costly and time-consuming endeavor. The finished product, however, is well worth the extra effort!

Carbon Fiber

Sportier watches, especially those inspired by racecars, call for the use of carbon fiber dials. Like mother-of-pearl, they sometimes need to be custom-cut to fit the dial design, but we gladly take the time to give each and every timepiece the finish it deserves. The Phantom Tourbillon is one example; the carbon fiber had to be cut at 6 o’clock to accomodate the open heart tourbillon complication.

Cases

From our tourbillons to our most basic quartz timepieces, each case design comes directly from schematics drawn up by our own expert watch engineer; none of Stuhrling Original’s cases are ever bought from a third party – they are all created in-house at our Swiss-owned factories. If we want a new case design, it is designed from scratch. Furthermore, these cases are never cast from a mold to speed up the process of production. Each individual case is blanked from bars of solid stainless steel to ensure strength, durability, and quality.

Movements

We use a variety of movements, but we are known for our mechanical automatic timepieces. Many of our fans wonder what the caliber number means. The “ST” in front of the caliber number stands for “Stuhrling,” and it denotes a movement that has been individually calibrated by our own watchmakers before we use them in any case. Stuhrling Original will always check a movement for its accuracy and functionality before using it any of our timepieces, and this extra step ensures the highest quality and most reliable timepieces possible for our brand. It is a painstaking and time-consuming process, but the end result is worth it.

Crystals

Krysterna is a material used exclusively by Stuhrling Original. It is a product engineered by the eyeglasses industry, and it is designed to be more shatter-resistant than sapphire. You will find this material in most Stuhrling Original timepieces. We are also known to use sapphire crystals for many of our tourbillon models.

Sneak Preview: Stuhrling Original’s BRAND NEW Phantom Tourbillon!

Solid Ceramic Case
Solid Ceramic Bracelet
Sapphire Crystals
Genuine Carbon Fiber Dial
Genuine Tourbillon Movement

Coming soon…

Purity

The first of many from Stuhrling Original, the Purity is a beautiful addition to our collection, as it is a ceramic watch! It’s incredible beauty comes from the the high polish found throughout the timepiece; from case to bracelet, you will find that the Purity simply shines!