Strap for Portofino Automatic Yellow Gold / Black - Pilot / Strap

The lug width of the IWC Portofino IW3513-08 is precisely 18 millimetres. This dimension is standard for this model and was selected by IWC to maintain balanced proportions with the 34-millimetre case. When changing the strap, measure the space between the internal lugs with a digital calliper to ensure aftermarket compatibility.

Alligator leather is the natural choice: its discrete grain complements the warm tone of yellow gold, and the patina developed over time visually synchronises with the metal's ageing. Shell cordovan of elevated quality is equally excellent, offering dense fibre structure that guarantees longevity beyond five years of daily wear. For formal occasions, black calf leather provides sharp contrast and understated refinement.

The procedure requires a spring bar tool with two shaped tips. Insert one tip to lift the internal spring mechanism inside the lug whilst the other maintains equilibrium. Rotate gently downward to release the spring bar. Repeat on the opposite lug. When reinstalling, secure one end of the spring bar into the lug first, then press the strap to fully engage the mechanism. If uncertain, a professional watchmaker completes the procedure in minutes.

Yes, any strap with an 18-millimetre lug width is compatible. Quality aftermarket straps offer extensive personalisation in material, colour, and finish. MilanoStraps supplies 18mm straps in alligator, calf, shell cordovan, and technical textiles, all engineered to fit without forcing or friction. Construction tolerance remains within 0.2 millimetres.

A quality alligator or vegetable-tanned calf strap lasts approximately 3-5 years with daily wear, provided exposure to humidity is moderate and direct heat sources are avoided. Shell cordovan extends to 5-7 years owing to fibre density. Ageing is part of the aesthetic: the strap does not deteriorate but develops a patina reflecting the wearer's lifestyle. Atelier Casati Milano provides 18-month warranty on all bespoke straps and offers repair services to extend useful life.