Strap for Portugieser Automatic 40 Stainless Steel / Green

The lug width of the Portugieser IW3583-10 is 20 mm. This dimension represents the distance between the left and right lugs at the base of the case and is specific to this model. It is essential to measure it with precision before purchasing a strap, as even half a millimetre discrepancy creates unwanted play or blocks the rotation movement.

For the Portugieser IW3583-10, we recommend three options: vegetable-tanned alligator for those seeking formality and natural patina over time, structured Spanish calf for more robust daily use, NATO woven polyamide for those using the watch in maritime or sport-casual contexts. Your choice depends on your lifestyle and frequency of wear.

To change the strap on an IWC, you need a quality spring bar removal tool. Position it between the case and the strap to push inward the spring pin, forcing it to exit the housing. Repeat from the opposite side. When inserting the new strap, align the holes and press firmly until the pin clicks into position. If unsure, consult a professional watchmaker.

Yes, any aftermarket strap with a 20 mm lug width is compatible with the Portugieser IW3583-10. However, it is advisable to choose artisan-quality straps that respect the aesthetic proportions of the case and offer finishes (stitching, edge finishing, buckle quality) consistent with IWC standards.

A high-quality leather strap with vegetable tanning lasts on average 4–6 years with daily wear. Lifespan depends on frequency of use, water exposure, and maintenance. An alligator strap tends to last longer than calf leather thanks to its more compact and resistant fibre structure. The Casati Milano atelier offers an 18-month warranty on all straps.