Strap for Pilot's Watch Spitfire Double Chronograph Stainless Steel / Black / Spanish / Strap

The lug width of the IWC Pilot IW3713-35 is precisely 21mm. This measurement represents the internal distance between the two lugs on the case and is the essential parameter for purchasing a compatible strap. To verify, use a digital calliper positioned on the inner part of the lug seat, avoiding measurements on the outer edges which would produce inaccurate readings.

Given the avionic and sport profile of this model, we recommend black alligator with beige thread stitching, which maintains military aesthetics without competing with case robustness. Alternatively, vegetable-tanned calf leather develops a patina that parallels the steel aging process, whilst shell cordovan offers natural water resistance and rigidity for operational contexts. NATO straps remain valid for high-wear activities.

Changing the Pilot strap requires a spring bar removal tool specifically designed for wide lugs. Position the watch with the lug side facing upward, gently insert the tool tip into the small lateral groove of the lug pin, compress slightly and slide the pin out of the seat. Repeat for both lugs. Insert the new strap by reversing the procedure, ensuring the pins click correctly into position.

Yes, you can use high-quality artisanal compatible straps provided the lug width is exactly 21mm. Premium aftermarket straps crafted from alligator, calf, cordovan or vegetable leathers preserve the aesthetic and functional integrity of the watch, and indeed permit customisation impossible with factory options. Precise lug measurement before ordering is essential.

The lifespan of a leather strap depends on tannage, usage and climatic conditions. A well-maintained vegetable-tanned calf strap lasts 3-5 years with daily wear; shell cordovan, due to its density, easily reaches 5-7 years. High-quality alligator straps can last 7-10 years. Exposure to perspiration, humidity and UV rays accelerates ageing. Regular maintenance (application of natural wax, drying after wetting) significantly extends longevity.