Strap for Portofino Automatic 37 Stainless Steel / Grey

The lug width of the Portofino IW4586-03 is 18mm. This intermediate measurement, taken between the lug pins, is specific to this model and requires straps crafted with proportions that maintain the aesthetic balance of the slender 37mm case.

Alligator is the noblest choice: its angular texture contrasts elegantly with the polished steel and develops a captivating patina over time. Shell cordovan with vegetable tanning offers a sublime alternative, thicker and more practical. Perforated calf ensures breathability, while FKM rubber is the boldest and most contemporary choice, virtually indestructible.

Use a caliper or ruler to measure the space between the two lugs of the watch case (not the distance between the lug pins). For the Portofino IW4586-03 the result will always be 18mm. This measurement ensures that the strap you order will fit perfectly without play or friction.

Yes, all straps with 18mm lug width are compatible. Milanostraps offers a selection of handcrafted 18mm straps ready to ship, customizable in size, initials, and stitching thread color. What matters is verifying that the keeper is proportioned to the slender case so as not to alter the visual balance of the watch.

With ordinary care, an alligator or cordovan strap lasts 2-4 years before requiring restoration. Perforated calf tends to wear more quickly in the bending zones (approximately 18-30 months). Straps made with vegetable tanning age naturally and become more interesting over time. Casati Milano provides an 18-month warranty on all bespoke straps.