Patek Philippe

Patek Philippe 3418

Oct 07, 2021,17:23 PM

To the untrained eye, this is your run-of-the-mill dress piece from Patek Philippe, but to those who know what they're looking at (or have had the distinct pleasure of unscrewing an example's caseback) it's anything but. In truth, this is a tool watch , through and through, designed with the meddling effects of magnetic fields in mind. On top of that, it's an exceedingly rare reference, and one that I was fortunate to acquire.

**NOTE by FabR (Patek moderator): The remaining portion of this text is taken from the following Collectability article, authored by John Reardon:**

collectability.com

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During the late 1950s, Patek Philippe developed and marketed its first anti-magnetic wristwatch references. These watches were made in response to increased demand for high quality Swiss watches that could be used by professionals who had constant exposure to high degrees of magnetism such as electrical engineers, scientists and doctors. In such professions, a normal, non-protected watch would be rendered useless.

Patek Philippe produced the stainless steel Ref. 3418 for just four years, beginning in 1958. Throughout this limited production run, examples were fitted with the manufacture's nickel-finished Cal. 12 AM 400 (first series) or Cal. 27 AM 400 movement (second series), with soft-iron protective shielding. This innovative construction protected the timepiece's crucial components from being hindered by magnetic fields, which can damage a mechanical movement. Like the Rolex Milgauss of the same era, these watches would've been sold to professionals working in scientific fields, where such forces were very much present.

With Patek’s Amagnetic watches, the most sensitive parts of the watch, the anchor and escape wheel, were made using non-magnetic metals such as gold. In addition, numerous alloys had been proven capable of withstanding magnetism, namely Invar (composed of iron, nickel, carbon and chronium), Glucydur (berylium and bronze), and Nivarox (iron, nickel, chronium, titanium, and beryllium). Since the late 1950s, most Patek Philippe watches have been fitted with Nivarox hairsprings to help prevent magnetism. The first anti-magnetic caliber utilized in a Patek Philippe wristwatch was the caliber 12 AM 400 (AM representing anti-magnetic). Launched in 1958, this caliber was fitted with a gold or beryllium lever escapement and had a protective soft iron cap. These watches were designed to withstand magnetic fields of up to 450 oersteds.

This unusual watch complemented Patek’s steel tool watch offerings of the era and was available for purchase concurrently alongside the ref. 3417. While over 500 examples of the ref. 3417 were reportedly made, it is estimated that fewer than 100 examples of the ref. 3418 were made and very few of these watches have surfaced to date.

The 35 mm cases of the ref. 3418 were made by Jean Vallon in Neuchatel and the bracelets by Cornu & Cie in La-Chaux-de-Fonds. An interesting fact is that the buckles of their bracelets were typically signed ‘UNROC’, Cornu backwards. Available with the option of silvered or black dials, this classic reference is as understated as it is functional. The original price was not inexpensive for the time, at $1,000 USD suggested retail.