1980s IWC Ingenieur SL Automatic Ref. 3506 Grey 'Graph Paper' dial

The IWC Ingenieur SL ref. 3506 is a notable piece within IWC's Ingenieur line, designed with technical prowess and iconic styling.

 

The Ingenieur series started in 1955 as IWC's answer to antimagnetic tool watches, catering to engineers, scientists, and others who needed watches resistant to magnetic fields. The initial models were robust yet relatively understated in design, focusing primarily on function.

 

In the 1970s, IWC brought in Gérald Genta, the legendary watch designer behind iconic sports watches like the Audemars Piguet Royal Oak and the Patek Philippe Nautilus. Genta's influence led to the creation of the Ingenieur SL (ref. 1832) in 1976, known as the “Jumbo” for its substantial 40mm case. It featured a signature integrated bracelet, exposed screws on the bezel, and angular case design, giving the Ingenieur line a distinctive luxury sports watch appeal.

 

Released in the 1980s, the Ingenieur SL ref. 3506 continued the design evolution. This model was slightly smaller than its predecessors, coming in at 34mm, yet retained many of Genta’s original design cues—an integrated bracelet, prominent bezel, and rugged construction.

 

The ref. 3506 featured significant advancements in magnetic resistance, with an inner iron case shielding the movement. It was powered by IWC's automatic caliber 3755 (based on an ETA movement), offering reliability and accuracy.

 

Though initially less popular than IWC’s larger models, the ref. 3506 gained appreciation over time for its Genta-inspired design, wearability, and solid engineering. Today, it's a respected piece among collectors, valued for its place in the history of luxury sports watches and as a more compact expression of Genta’s design philosophy.

 

The ref. 3506 was made in steel, two-tone (steel and yellow gold) and in yellow gold.

 

In summary, the IWC Ingenieur SL ref. 3506 stands as a refined iteration of the Ingenieur lineage, embodying technical sophistication and timeless style.

Offered for sale here is a IWC Ingenieur SL Ref. 3506 in stainless steel from circa 1980.

 

The grey 'Graph Paper' dial is preserved in very good condition, with minor signs of wear. It features gold-tone accents, such as gold-colored indices and hands. The lume plots remain intact and present a lovely creamy patina hue matching that on the hands. These accents match the gold elements on the case and bracelet. This creates a cohesive look for these two-tone versions.

 

The cushion-type case, in stainless steel, remains in great condition, leaving very little visible wear, if any. The case back is in the same condition, showing however some tool marks.

 

The IWC stainless steel integrated bracelet with deployant clasp coded R12 remains also in strong condition, with normal signs of use. It has no visible stretch.

 

The sapphire crystal is clean, except for a small ding at around 7.

 

The watch is running well and keeping time, although service history is unknown.

 

Macros of dial and case are available under request.