Essential specifications for modern society
Living in modern society, we are surrounded by more powerful magnetic fields than we can imagine. Examples are endless, starting with the most familiar electronic devices such as mobile phones and tablet devices. In fact, magnetism is the enemy of watches, causing them to lose their accuracy, whether they are mechanical or quartz. Despite this, the reality is that there are very few wristwatches with high magnetic resistance.
In this feature, we will focus on high magnetic resistance, which is now considered an essential specification in modern society, and teach you how to prevent your watch from becoming magnetized. We will also examine the capabilities of currently available high magnetic resistance watches.
Photographs by Masanori Yoshie
Illustrations by Maiko Kato
Why is antimagnetic technology necessary in modern society?
Over the past 20 years, the wristwatch as a practical item has come close to perfection. There are three reasons for this.
First,The precision of the case processing has been improved, and the case material has been replaced with highly corrosion-resistant 316L and titanium.こと.
nextThe crystal has been changed from plexiglass or tempered glass to sapphire crystal.こと.
in addition,Waterproof packing materials have also evolvedAnd it's hard to complain about the water resistance and durability of watches these days.
However, even in the 21st century, one weakness remains untouched: antimagnetic properties.
Many metal parts are used inside watch movements, whether quartz or mechanical. Most of these are ferromagnetic, meaning they are easily magnetized, meaning they are easily attracted to magnets. Examples include the steel used in the pinion, balance shaft, escapement, and winding stem, the nickel used in the balance wheels of inexpensive ebauche movements, and the Invar and Elinvar alloys used in hairsprings.
When such ferromagnetic materials come into contact with magnetism, it causes mechanical watches to slow down or stop, and quartz watches with built-in step motors to stop. In the case of quartz watches, removing the watch from the magnetism will cause it to resume normal operation (though there are exceptions). However, in the case of mechanical watches, the accuracy will not recover even if the watch is removed from the magnetism due to the influence of residual magnetism (residual magnetism). This state is called "magnetization," and unless the remaining magnetism is eliminated, the watch will not return to its original state.
In the past, watches rarely became magnetized. The only exceptions were environments where strong electric currents flowed (electric currents generate magnetism), but these were limited to places like power plants, the inside of electric locomotives, and near radar and broadcasting equipment. In response, watch manufacturers released "ultra-magnetically resistant watches" that were resistant to magnetism and aimed at operators and professionals who worked on such equipment. However, the average person was not likely to be in an environment where a watch could become magnetized, so these ultra-magnetically resistant watches never gained widespread acceptance.
(Center) Men's magazines recommend layering watches and accessories. It doesn't matter what you wear, but magnetic accessories with built-in magnets are strictly prohibited. They emit a magnetic force of at least 10 A/m (when in close contact), so if they are in close contact with a watch, magnetization is almost inevitable. Wearing them on the opposite arm might be okay, but there's no guarantee they won't hit the watch.
(Right) Magnetic snaps used on bags, cell phone cases, etc. are the biggest cause of magnetization in watches. While this varies depending on the type and shape of the magnet, the magnetic force can range from approximately 2 to a maximum of 27 A/m (when in close contact). Watch enthusiasts should try to keep items with magnetic snaps as far away from them as possible.
However, we are now surrounded by magnetism. What is posing a problem is not the magnetism generated by electric currents, but the magnetism generated by magnets themselves, which was previously unimaginable.
In 1984, Japan's Sumitomo Special Metals (now Hitachi Metals) developed neodymium magnets, primarily composed of neodymium, iron, and boron. These magnets had more than five times the magnetic force of existing magnets, and since then, magnets have become much smaller. Magnetic health devices, mobile phones, and portable audio equipment are some of the products that have benefited the most from neodymium magnets. The new magnets also popularized magnetic snaps used on bags and other items. While these were invented in 1972, they would never have become so popular without the use of small, powerful magnets.
Powerful magnets were once rare in our daily lives. However, they have now become an indispensable part of our daily lives, and as a result of their miniaturization, it has become difficult to know where they are used. In the past, it was common sense to keep watches away from places where there was a risk of magnetism. However, today, magnets are lurking all around us, often in ways we don't even notice. Even if you use them carefully, it is probably difficult to prevent your watch from becoming magnetized.
*Not all products were tested.
*There are individual differences in the strength of the magnetic field even for the same product.
(According to Seiko Watch)
From what I've seen and heard, the majority of everyday malfunctions are caused by magnetism. It's also safe to say that the majority of watches brought in for repair are magnetized to some degree. It's particularly difficult to find a non-magnetized watch, especially among repeaters and chronographs, which use a lot of steel components. In fact, a veteran watch technician at one service center said, "At least one-third of the watches brought in for repair are magnetized. In my opinion, in a magnetic field of 20 to 30 gauss (= 1600 to 2400 A/m), a mechanical watch will lose about 20 to 30 seconds per day."
So, now that magnetism in watches is unavoidable, how can you protect your watch from magnetism? While keeping your watch away from magnetism is a given, there is one effective solution: encasing the entire movement in a "soft magnetic material." This is a classic, but extremely effective solution.
