Avoiding the hassle of magnetizing your mechanical watch: Introducing countermeasures and anti-magnetic watches

Magnetism, the arch enemy of mechanical watches, is a nuisance that plagues watch enthusiasts. In this article, we will explain what causes magnetism in watches, what to do if your watch becomes magnetized, and introduce three current models that boast excellent magnetic resistance.

What is "magnetism" in mechanical watches?

　Magnetism is one of the biggest enemies of mechanical watches, which have movements that use ferromagnetic metal parts. Magnetism lurks in various places in modern society, and is even invisible to the naked eye. If we are not conscious of it every day, the inside of the movement, especially the balance spring, will be affected by magnetism and will no longer function properly; in other words, it will become magnetized. When magnetized, the movement of the escapement, which controls the accuracy of the watch, will be disrupted, resulting in symptoms such as the time running fast or slow.

　Examples of common magnetic objects include smartphones, computers, earphones, magnetic necklaces, bag clasps, and even magnetic sheets attached to the walls of elevators. If you wear a mechanical watch, you should be careful not to bring it near these objects.

　It's easy to forget, but analog quartz watches can also become magnetized. Although they are less susceptible to magnetism than mechanical watches, exposure to strong magnetic fields can cause the hands to stop moving or their accuracy to be affected. There's no need to worry, but you should be careful when handling strong magnets.

Things you need to know to prevent your mechanical watch from becoming magnetized

　So how can you use a mechanical watch without it becoming magnetized? The only way is to keep the watch away from magnetic sources. Most modern watches can avoid magnetization by keeping them 5cm away from the source of the magnetic field. The Japanese Industrial Standards (JIS) define a watch that can withstand magnetic fields up to this distance (or a DC magnetic field of 4,000A/m) as a Class 1 magnetically resistant watch, and if the specifications state this, you can rest assured. Even more advanced Class 2 magnetically resistant watches can be brought up to 1cm away from a magnetic source (a DC magnetic field of 16,000A/m).

　Even if you use your watch carefully, it is not uncommon for it to become anti-magnetic without you realizing it. If your watch suddenly becomes less accurate, but you think it's still a while before it needs an overhaul, the first thing to check is whether it has become magnetized. It's easy to check whether your watch has become magnetized. If the compass needle wobbles when you bring it close to the watch, it is likely that your watch has become magnetized.

　In most cases, magnetism in a watch can be removed by passing it through a demagnetizer. Demagnetizers are available commercially, so you can purchase one and do the job yourself, but if you handle it improperly, you could end up magnetizing the watch again, so we recommend taking it to a watch shop.

　Some watches have excellent magnetic resistance, meaning they are resistant to magnetism even when exposed to strong magnetic fields. There are two main approaches to improving magnetic resistance. One is to use a soft magnetic inner case. The movement is surrounded by a soft magnetic material, such as soft iron, which deflects surrounding magnetic fields and prevents them from reaching the interior. This is a standard method that has been used by various companies for many years, and the mechanism is simple. However, the downside is that the inner case makes the watch itself heavier and thicker.

　Another approach is to use non-magnetic materials for the movement components themselves. The most common method is to dramatically improve magnetic resistance by using silicon for the balance spring, which is particularly prone to magnetization. However, silicon balance springs cannot be fitted with a regulator, with a few exceptions, and precision must be adjusted using a screw on the balance wheel. Because there are limits to this adjustment, the processing and assembly precision of the components must be high to begin with. Implementing this material calls into question the brand's manufacturing technology.

Introducing anti-magnetic watches that you can use with peace of mind!

　Below, we will introduce three current anti-magnetic watches. If you want to avoid magnetism, you should use these models as a reference when choosing a watch. Each company has its own ingenious way of overcoming magnetism, so it's interesting to compare the differences.

Omega Seamaster Planet Ocean Ref. 217.30.42.21.01.001

　The Omega Seamaster Planet Ocean was redesigned into its fourth generation in 2025. It features an iconic dial with Arabic numeral indexes and arrow-shaped hour and minute hands, and a sharper case with a completely redesigned design. The helium escape valve at 10 o'clock has been removed, and a sleek crown guard has been added, giving it a more modern and sophisticated look. Despite being a high-spec diver's watch with a water resistance of 600m, the case thickness is also attractive, being kept to less than 14mm.

　The straps are available in a variety of stainless steel bracelets with polished and hairline finishes, as well as rubber straps for a lighter feel.

　Most current Omega watches are Master Chronometer-certified by the Swiss Federal Institute of Metrology (METAS), which requires a watch to be able to withstand a powerful magnetic field of 15,000 gauss. Omega meets this high standard by using a silicon balance.

Tissot "Tissot PRX Automatic" Ref. T137.407.11.041.00

　Tissot, a pioneering watchmaker, introduced the world's first antimagnetic wristwatch in 1930. Inspired by a model released by the company in the 1970s, the Tissot PRX is a popular collection featuring a case with an integrated bracelet reminiscent of a luxury sports watch. The sunray blue dial with a grid pattern makes it easy to wear both on and off the job, and it's highly practical, with a date display at 3 o'clock and thick, clear hour and minute hands coated with luminous paint.

　The stainless steel case has a solid impression with a hairline finish. In addition to the stainless steel bracelet, rubber straps and leather straps are also available, and the interchangeable system makes it easy to change straps.

　What gives this watch its excellent anti-magnetic properties is the Nivachron™ hairspring. Nivachron™ is an alloy primarily composed of non-ferrous materials, titanium and niobium. Although it contains trace amounts of iron, it offers dramatically improved anti-magnetic properties compared to conventional hairsprings. Nivachron™ also offers other benefits, such as easier maintenance than silicon, which is prone to cracking, and the ability to use a regulator.

Sinn "613 St" Ref.613.012

　This high-spec diver's chronograph is Sinn's new model for 2025. The black dial contrasts with the white indices and hands, ensuring excellent visibility. A deliberately less legible gray small seconds hand is located at 9 o'clock. The large subdial at 6 o'clock is a 60-minute counter used when measuring time with the chronograph. The tips of the counter hand and the central chronograph second hand are unified in red to prevent confusion with the time display hand.

　It also features numerous Sinn technologies, including Ar-Dry Technology, a dry capsule embedded in the side of the case, protective gas filled inside the case, and EDR packing to prevent moisture from entering. Other features include a unidirectional rotating bezel with a special coupling system that prevents it from coming off the middle case even when subjected to impact, the D3 system that allows push buttons to be operated underwater, and Magnetic Field Protection, which uses a soft magnetic ring, dial, and case back to achieve high magnetic field resistance of 80,000 A/m.