Strap for Pilot's Watch Spitfire Double Chronograph Stainless Steel / Silver / French / Bracelet

The lug width of the IWC Pilot IW3713-49 is 21mm. This dimension represents the distance between the two lugs of the case and determines which strap is compatible with the watch. To verify, measure the distance from the inner side of the right lug to the inner side of the left lug across the case diameter. All 21mm straps will fit this model correctly.

For the IW3713-49, we recommend premium leather options such as vegetable-tanned alligator or natural vegetable-tanned calf. Alligator offers structural rigidity and patina that develops naturally over time, perfect for formal settings. Vegetable-tanned calf provides daily versatility and aesthetic compatibility with the dark blue dial. For a sportier heritage style, a fabric NATO strap is appropriate; for humid environments, technical FKM rubber is the most reliable choice.

Strap replacement is performed using a spring bar tool. Locate the two metal pins inside the lugs, apply gentle pressure to one pin to release the old strap, then remove it. Insert the new strap aligning it with the lugs and ensure both pins click into position. Verify that the strap is firmly secured at both ends before wearing the watch. If you lack experience, a professional watchmaker can perform the change in minutes.

Yes, any strap with a 21mm lug width is compatible with the IW3713-49. Online you will find various pre-made options from different brands, but bespoke artisanal straps offer superior quality and the ability to choose the leather, colour, and exact length. Atelier Casati Milano produces custom straps specifically for this lug width, with 18-month warranty and update service.

A quality leather strap—such as alligator or vegetable-tanned calf—lasts between 3 and 5 years of daily wear, depending on maintenance and sun exposure. Vegetable-tanned leather develops a natural patina that can enhance aesthetic appeal over time. With proper care (avoiding prolonged bathing, protecting from prolonged direct sunlight), longevity extends. Straps made by Casati Milano include an 18-month warranty and can be regenerated by specialist watchmakers even after years of use, as the construction respects durable sartorial standards.