Both Rolex and IWC saw the need for a watch for engineers and scientists in the 1950s, combining rugged automatic movements, water-resistant cases, and anti-magnetic concepts in the Rolex Milgauss and this IWC Ingenieur. The concept has remained for over 50 years, with the IWC Ingenieur family spawning many models, including an iconic redesign by famed designer Gerald Genta, a pivot to motor racing, and the use of exotic materials like titanium and ceramic.
The first Ingenieur models, Ref. 666A and 666AD (with date), appeared in late 1954, with most sales beginning in 1955. It a up-to-date tripartite case with a screwed-on caseback with an integrated soft iron inner case and dial back for resistance to magnetic fields. The case was large for the time at 36.5 mm diameter and thick at 13.2 mm due to the soft iron inner case. Combined with the plain styling and well-defined lugs, this gives the original reference a modern feel. The pie pan dial and dauphine hands, however, feel somewhat dated. All Ingenieurs have the “INGENIEUR” logo above the index at 6 00.
The most common Ingenieur was the Ref. 666A and 666AD, which had a steel case. These were available on either a leather strap or steel bracelet and 18 karat gold filled versions were produced as well. The Ref. 766A/766AD were identical but used a 14 karat yellow gold case and steel caseback.
In 1959, IWC updated the movement in most watch models to Cal. 853/8531 which featured an improved barrel and adjustment screws on the balance. The Ingenieur references remained the same, as did the case and specifications. A beads-of-rice bracelet by Gay-Frères along with a gold “brick” bracelet was also introduced around that time, becoming Ref. 9033 and 9386, respectively. By this time, models with the date complication had become much more popular, so some non-date references went out of production or became scarce. IWC also added a prefix and suffix to the reference number for a few years in the mid-1960s, resulting in reference numbers like 26662, 36661, 56662, 66661, 76662, 87661, and 993861. The suffix “1” or “2” indicated date or no date, respectively, while the prefix indicated the case and strap combination.