Strap for Portofino Automatic 37 Stainless Steel / Silver

The lug width of the IWC Portofino IW4586-01 is 18 mm, a specific standard for this model. The measurement is obtained by calculating the distance between the centers of the holes from which the lugs emerge. This width is distinctive for the Portofino and differs from the more common 20 mm, requiring careful selection of compatible straps.

For the Portofino IW4586-01, straps in natural alligator leather with vegetable tanning, artisanal rigid calf, or shell cordovan are recommended. These materials respect the classical and refined character of the watch. Alligator offers a natural grain that captures light delicately; calf guarantees a uniform texture that ages well; shell cordovan develops a rich patina over time. For a versatile approach, a cotton-linen NATO strap is also available.

To change the strap on the Portofino IW4586-01, you need to remove the spring bars that secure the strap to the case. Using a specialized tool (spring bar tool), gently press the pin until it disengages, then remove the old strap. Insert the new 18 mm strap and verify that both spring bars lock completely in their respective lugs. If you are unfamiliar with this operation, an experienced watchmaker can perform it in minutes without risk to the case.

Yes, you can use any aftermarket strap with an 18 mm lug width, provided it is of good construction quality. Artisanal straps available online are compatible with the Portofino as long as they comply with metric standards. We recommend choosing noble materials (alligator, shell cordovan, vegetable-tanned calf) that maintain the classical aesthetics of the watch. Avoid synthetic or glossy leather straps, which would conflict with the refined character of the satin-finished case.

The lifespan of an artisanal leather strap depends on the materials and usage. A vegetable-tanned calf strap lasts 3-5 years with moderate daily use. A natural alligator strap can last 6-8 years. Shell cordovan is the most resistant, with a potential lifespan of 10+ years. Deterioration typically begins on the inside of the strap (wrist side), where perspiration and humidity accelerate aging. Proper maintenance—regular cleaning and quick drying after water contact—significantly extends the life of the strap.