Strap for Portofino Chronograph 150 Years Stainless Steel / Blue

The lug width of the IWC Portofino IW3910-23 is 20mm. This dimension corresponds to the precise distance between the two pins that attach the strap to the case lugs. It is essential to verify this measurement with a calliper before ordering an aftermarket strap, as variations of 0.5mm can create tension on the case.

Alligator leather represents the ideal choice for the IW3910-23: the regular grain texture creates an elegant contrast with the stainless steel case, and the hide absorbs humidity variations without transmitting rigidity to the wrist. Valid alternatives include shell cordovan for a more refined finish, vegetable-tanned calf leather for a patina that evolves over time, and FKM rubber for summer or sporting contexts.

Strap replacement is accomplished by extracting the pins present at the case lugs. Using a spring bar tool, apply pressure to the lower pin to release the strap; subsequently insert the new strap by aligning the holes with the lugs and ensuring the pin clicks firmly into position. It is advisable to work on a soft surface to avoid scratching the case caseback.

Yes, provided the lug width is exactly 20mm. Aftermarket straps of quality guarantee the same functionality as OEM straps, with the advantage of a wider aesthetic selection. Atelier Casati Milano produces bespoke straps specifically calibrated for the IW3910-23, with 18-month warranty and customisation options in leather, colour, and stitching thread.

A quality natural leather strap (alligator, shell cordovan, calf) has an average lifespan of 3-5 years with daily wear, varying based on ambient humidity and frequency of use. Vegetable tanning develops a protective patina that tends to extend durability; shell cordovan is particularly resistant to stress. Periodic maintenance with leather-specific balms can extend the strap's longevity by 1-2 years.