Strap for Portofino Automatic Moonphase Stainless Steel / Blue / Alligator

The lug width of the IWC Portofino IW4594-02 is 20mm. This measurement represents the distance between the two internal anchor holes in the case where the spring bar of the strap is inserted. It is essential to verify this dimension before purchasing any aftermarket strap to ensure mechanical compatibility and prevent damage to the attachment pins.

The optimal material depends on the context of use. For formal environments, alligator with vegetable tanning offers uncompromising elegance and a patina that naturally evolves. Calf leather, similarly vegetable-tanned, adds narrative character to the timepiece. For daily executive use, a grey NATO or black rubber strap ensures versatility and practicality whilst maintaining the constructive authority of the model. Shell cordovan represents the choice for those who appreciate leather evolution over time.

Strap replacement requires removal of the attachment pins (or spring bars) connecting the case lugs to the strap. Use a dedicated spring bar tool or consult a qualified watchmaker. The case's spring bar must not be forced — the pin entry into the lug holes should be fluid. Once the pins are removed, the old strap separates from the case. Installation of the new 20mm strap follows the reverse procedure, ensuring the pins fully engage the lug holes without mechanical play.

Yes, provided the strap is correctly dimensioned at 20mm lug width. A quality aftermarket strap, crafted from premium alligator, calf, or rubber, is fully compatible and allows aesthetic variations from the standard issue. However, it is essential to source from artisans who respect precise millimetric tolerances — poorly dimensioned straps create loose attachments that damage both the strap and the case pins.

Longevity depends on frequency of wear and leather quality. An alligator or vegetable-tanned calf strap, worn daily under normal conditions, typically lasts 3–5 years. Primary wear manifests at the keeper and in the fold zone near the buckle. With moderate wear (3–4 days weekly) and appropriate maintenance—avoiding prolonged water contact and high humidity—lifespan extends to 7–8 years. A rubber or NATO strap resists longer (5–10 years) due to material nature, though periodic cleaning is required.