Closed | Important watches – Saturday 15 November 2014

IWC launched their watch model Ingenieur in 1955 and was at that time together with Rolex Milgauss (1954), Patek Philippe Antimagnetic (1958) and Jaeger-Le Coultre Geophysic (1958) the most antimagnetic watch on the market, developed for people working close to strong magnetic fields. The Ingenieur has been evolved and refined a couple of times since the 1950’s and one of the more unusual models is the SL (500.000 A/m) which only was made in about 2700 examples between the years 1989-1993.

This model was made to endure all magnetic fields, no matter how strong they were. One of the secrets behind its success was that the balance spring was made by a special alloy which made the inner safety case redundant. The model was tested over and over again and could withstand amazing 3.7 million A/m (ampere per metre). However, since the technology to test anti magnetism on this level wasn’t fully developed in the 1980’s, IWC chose to be careful and put 500 000 A/m as the official test result. The modified balance spring showed to be extremely sensitive for temperature changes though, that’s why the movements didn’t pass to get a chronometer certificate by C.O.S.C.

Despite being the most antimagnetic watch ever made for the public, enduring up to six times as much magnetism as the antimagnetic models do today, the watch came to be a failure for IWC. But much because of the small edition, the Ingenieur SL (500.000 A/m) has become a collectors item. Reference 3508 in steel/gold, like the one we have up for sale, is said to only have been made in 340 examples.