This ref. 3508 Ingenieur is one of the most antimagnetic watches ever made, the first watch with a nobium hairspring, and just 34mm. It is one of the most technically accomplished Ingenieurs, but mostly overlooked today. IWC asked their engineers in 1989 to make an extremely antimagnetic calibre. That’s like telling Rolls-Royce to make a very quiet interior. They were already prepared and brimming with ideas, with the reins off IWC’s ambition new no bounds. What resulted is one of the finest attempts at extreme magnetic isolation in a wristwatch. For comparison the famous Rolex Milgauss is so named for its 1,000 Gauss resistance, which is only about 80K A/m.
Many readers will be familiar with the Jumbo Ingenieur, SL or otherwise. And most will also know there was a midsized 34mm alternative. But the 500000 A/m ref. 3508 is neither. It’s an undeservedly overlooked small-run 34mm Ingenieur that could withstand a ridiculous 500K A/m. To put that in perspective, an average small MRI is 1000K A/m (some get larger, thanks to our resident Ph.D @siemswatches for pointing out). The average junkyard electromagnet, the thing that sucks up metal i-beams and cars like paperweights is 795K A/m. This case will be pulled off your wrist by magnetic attraction long before its field effects the timekeeping inside. This, thanks to both a soft iron Faraday cage and, more impressively, hairspring made from pure niobium-zirconium. The modifications were made to a what IWC called the calibre 37590, a highly modified ETA 2892-A2. That alloy proved so expensive to make, for hairsprings, that IWC lost money on every 3508 sold (even with the ETA ébauche). Rolex only figured out the niobium balance a decade later and called it Parachrom. The best bit, though, is that they engraved the accomplishment on the case flank for all to see.
The extreme resistance was developed originally not for the market, but for the German Military’s Bundeswehr. German divers needed totally a-magnetic watches for mine disposal, to not interfere with electric fields at all. This Ingenieur is actually more related to the 3H Ocean 2000 than any Genta peer. The 500K ref. 3508 was the consumer-marketed version of that tech, just 50 a-mag calibre Bunds exist from that initial development. This checks every single box for collectability: Genta, interest, story, world-first, and attractive design. But the market has yet to appreciate it as such. The size is its most divisive attribute, to put it bluntly. Seemingly, everyone loves the rest. Total production of the 3508 lasted just four years, during which it is estimated that around 1500 examples were made, of which fewer than 614 will be this steel only.
