Strap for Pilot's Watch Doppelchronograph Stainless Steel / Black / French / Strap

The IWC Pilot IW3713-04 is fitted with lugs measuring 21mm in width. This dimension is measured externally between the attachment points of the spring bar pins. It is essential to use straps specifically constructed for this measurement: 20mm straps will be too tight, whilst 22mm straps will be too loose, compromising both aesthetic alignment and the functionality of the lug passages.

For the IW3713-04, we recommend alligator straps with vegetable tanning in dark tones (chocolate brown or black): the natural grain echoes the technical aesthetic of the case, whilst the patina developed over time adds biographical depth to the timepiece. Alternatively, vegetable-tanned calf leather in robust thickness (1.4–1.6mm) or NATO straps in cotton aviation grey honour the military genesis of the watch. We advise against glossed or varnished leathers, which betray the functional character of the model.

Strap replacement requires extraction of the horizontal spring bar pins that connect the strap to the lugs. Use a dedicated spring bar tool to apply gentle pressure on one pin, liberating it from its housing, then extract carefully. Repeat on the other side. To refit: align the new pins with the lugs and push until audible click of closure. We recommend performing this operation on a clean, soft surface to avoid loss of the small pins.

Any strap constructed for 21mm lug width is compatible with the IW3713-04, provided it features standard spring bar pins (1.8mm diameter, conforming to IWC specifications). The artisanal 21mm straps from milanostraps.it are customisable in leather, texture, colour and thread, ensuring aesthetic coherence with the character of the model. Avoid generic or mass-market straps: manufacturing quality is determinant in preserving the integrity of the timepiece.

The longevity of a leather strap depends upon manufacturing quality, tanning method and usage. An alligator or vegetable-tanned calf strap, constructed artisanally with robust thickness (1.4–1.6mm), maintains structural integrity for 5–8 years of daily wear. Patina develops progressively within the first 18–24 months. Lower-quality or varnished leather straps have considerably reduced lifespan (18–36 months). Daily use in humid or perspiration-prone environments accelerates deterioration; prolonged ultraviolet exposure weakens the fibres. Periodic maintenance—conditioning with neutral oils—extends useful life considerably.