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Our world is in a constant state of change. Who would have expected 30 years ago that smart technology would evolve so rapidly and have such an impact on our everyday lives? Much of what our parents and grandparents had grown accustomed to and believed to be impossible to change has now disappeared from collective memory. Some things that we considered analogue and obsolete, however, are having a new, exciting moment. In this case, we’re referring specifically to antimagnetic watches. Numerous everyday objects, each with its own unique electromagnetic field have made it attractive again for watch manufacturers to produce timepieces whose accuracy is unaffected by magnetic forces.



What does antimagnetic mean?


First, let's clarify a few basic facts and definitions around the topic of magnetism. Basically, it's quite simple: items are antimagnetic if they have no attraction or interaction with magnets or their magnetic fields. However, the terms "antimagnetic" and "nonmagnetic" (or "amagnetic") can be found here and there. These can be explained precisely, because the difference between the two terms is in the details.


"Nonmagnetic" and "antimagnetic"

"Nonmagnetic" refers to a theoretical state in which a metal is completely free of any residual magnetism. This is a nearly impossible physical state, but nonmagnetic attributes of materials such as silicon are sufficient for classification as antimagnetic. The DIN standard 8309 defines that a watch may be called antimagnetic if it does not deviate more than 30 seconds per day under the influence of a magnetic field of 4,800 amperes per meter.


Back of the case of an anti-magnetic Omega Railmaster 220.12.40.20.01.001 watch
OMEGA RAILMASTER 220.12.40.20.01.001



Magnetism in our everyday environment


We all know the magnetic toy trains that attract each other with their differently polarised magnets. This effect also occurs with electronic devices. Current flows and a magnetic field are created with every movement of an electric charge. Today, we are surrounded by smartphones, laptops, induction fields and many other devices whose magnetic fields are stronger than we can imagine. For example, an iPhone has an output of 14,400 amperes per meter, and an induction field of 1.2 million amperes per meter. This corresponds to 15,000 Gauss. To understand these values better: a watch is considered antimagnetic if it does not deviate more than 30 seconds per day under the influence of a magnetic field of 4,800 amperes per meter.



The origins of antimagnetic watches


The fact that we are surrounded almost everywhere by magnetic fields is by no means a phenomenon of the 21st century. In the 20th century, the use of electricity in everyday life expanded due to the development of the railway networks, the advent of professional aviation and other new developments in technology. Watch manufacturers responded to the effects of this innovation by researching ways of protecting sensitive movements against the effects of magnetic fields. At the end of the 19th century, Vacheron Constantin began research and in 1915 introduced one of the first antimagnetic pocket watches. However, in the history of the watch industry the days of the pocket watch had long been numbered. In 1930, Tissot introduced the first series-produced wristwatch resistant to magnetic fields.

Its name, Antimagnetique, was as simple as it was fitting. This development continued and in the 1940s IWC developed a watch model for the Royal Air Force that was protected against magnetic fields using a Faraday cage. A Faraday cage is a shell made of an electrical conductor that is closed on all sides and shields the inside of the cage from electrical fields – cars and their conductive shells are a clear example of how a Faraday cage works.



What makes a watch antimagnetic?


​​If you want to produce an antimagnetic watch, it is necessary to first have an understanding of which watch components are susceptible to the effects of magnetic fields. The main magnetisable metals are iron, cobalt and nickel. Unfortunately, iron and nickel are important ingredients in conventional balance springs, which are primarily made of Nivarox. Consequently, these springs are quite easy to magnetise through an external, homogeneous, and temporally constant magnetic field. The resulting effect is that the balance spring shrinks together, the spring length is shortened and the balance oscillates much faster. If the magnetic bond of the balance spring is at its strongest, then the balance spring may even entirely lose its ability to oscillate, causing the balance wheel to stop So what can be done to prevent this?


Two Rolex Milgauss 116400GV watches with blue and black dials lie side by side on a mirrored surface
ROLEX MILGAUSS 116400GV | ROLEX MILGAUSS 116400GV


The soft iron cage

A simple way to make a watch antimagnetic is to protect the movement with a cage made of mu-metal. Mu-metal is an alloy of mainly nickel and iron, and other elements, which is characterised by its high magnetic conductivity. This cage conducts the electromagnetic field around the movement. To be effective against electromagnetic fields, this "cage" must be as completely sealed as possible. This is one of the reasons why many antimagnetic watches have no date window. These are watches featuring a "soft iron cage".


Silicon

Another way of shielding the movement from the harmful effects of electromagnetic charge is to avoid using ferromagnetic components, i.e. components that are sensitive to magnetic fields, in the construction of the watch. At the end of the 1980s and after the "quartz crisis", watchmakers' development centres were again in a position to work on the further development of materials for antimagnetic watches. Then in 2013, Omega presented the new Seamaster Aqua Terra equipped with the Calibre 8508, a movement made of silicon and NivaGauss, which was specially developed by Omega, and advertised as one of the first completely antimagnetic movements to maintain its resistance to magnetic fields without the need for a Faraday cage. Today, this type of nonmagnetic construction technique is virtually taken for granted. Antimagnetism was the beginning and nonmagnetism the future



Renowned antimagnetic watch models


The 1950s were a time of outstanding achievements in engineering. This also was reflected in the watches of that time, which illustrate the fascination with technology of that period in their own way. Several models stood out for their robustness and antimagnetic inner workings. Let's take a look at a few of the most famous antimagnetic and nonmagnetic wristwatches on the market.


IWC Ingenieur

IWC got its start in antimagnetic watches with the Ingenieur Collection, which was introduced in 1955. The IWC Ingenieur features a state-of-the-art Pellaton winding, system, named after the company's technical director, an improved Breguet overcoil, and a higher rate of oscillation. An inner case is made of soft iron to prevent magnetic fields from negatively affecting Ingenieur's functionality. This was well received by medical and engineering professionals. Its blend of straightforward elegance and robust construction made the Ingenieur one of IWC's best-selling watch models for a long time.


Anti-magnetic IWC Ingenieur IW3521 steel watch with white dial rests on a floral motif
IWC INGENIEUR IW3521


Rolex Milgauss

In 1956, Rolex launched the Milgauss, a watch model that could withstand magnetic fields of up to 1,000 Gauss. This made the watch especially suitable for researchers, engineers and doctors. In particular, it was designed to equip the employees of CERN, located near Geneva, with a resistant watch. This was also where the Rolex Milgauss' resistance was ultimately tested. The timepiece kept what its name promised: Milgauss is derived from the French word "mille" for thousand and "gauss" as a unit for magnetic flux density.


Close-up of a Rolex Milgauss 116400 steel watch with black dial and orange second hand in the shape of a lightning bolt
ROLEX MILGAUS 116400


Omega Railmaster

The Omega Railmaster was first launched after the Rolex Milgauss and the IWC Engineer, but Omega had already researched anti-magnetic watches in the early 1950s and, like IWC, supplied the British Air Force with magnetically resistant watches. Once a predecessor to the Railmaster, the Referenz 2777-2, was successfully tested on the Canadian market, and the path was clear for the establishment of the Railmaster. In 1957, the company launched the Railmaster and promoted it as a watch model designed specifically for railway employees and other professionals exposed to strong electrical currents. Like the Rolex Milgauss from its competitor, the Railmaster had a magnetic resistance of up to 1,000 Gauss. The series also demonstrated a high level of resistance by being revived twice by Omega management. The latest Railmaster models are now able to withstand up to 15,000 Gauss.


Close-up of an anti-magnetic Omega Railmaster 220.12.40.20.01.001 men's watch with steel case, black dial and grey fabric strap
OMEGA RAILMASTER 220.12.40.20.01.001



Other antimagnetic wristwatches at Watchmaster



  • The Frankfurt-based watch manufacturer Sinn offers an impressive timepiece in line with the company's utilitarian philosophy with the 857 UTC. Featuring exceptional resistance to magnetic fields of up to 80,000 A/m thanks to its soft iron cage, as well as water resistance of up to 200 meters, and a practical GMT function, the 857 UTC is a tool watch par excellence. The 857 UTC TESTAF Lufthansa CARGO (ref. 857.041) is a limited-run special edition featuring a 43 mm stainless steel case on a leather strap. Plan on budgeting about €2,800 for a model from this series.

  • The Jaeger-LeCoultre Geophysic 1958 Limited Edition (ref. Q8008520) offers a slightly more elegant look. This model comes with a 38.5 mm case diameter, water resistance to 100 meters, and an antimagnetic soft iron cage. Featuring a classic, straightforward dial and a precise automatic movement, the model foregoes any kind of complications, limiting itself to the hour, minute and seconds. Put a Geophysic watch on your wrist for Für a little under €8,000.

  • In typical Panerai fashion, the Luminor Submersible Amagnetic (PAM00389) measuring 47 mm, is decidedly bold and sporty. Thanks to its soft iron cage (according to the definition at the beginning of the article, the model's use of "Amagnetic" in its name is somewhat misleading), titanium case, the automatic caliber P.9000 is fully protected from magnetic fields of up to 40,000 A/m Additionally, this watch includes a date window, a small seconds display, and a water resistance of up to 300 meters – all for a price starting at €8,800.