Strap for Portofino Automatic Stainless Steel / White - Railroad / Strap

The lug width of the IWC Portofino IW3513-35 is 18 millimetres. This lug width is specific to the 34mm Portofino models and is a classical specification that IWC has maintained to preserve the correct proportions between case and strap. To verify compatibility, measure the space between the two shoulders of the lugs on your watch: it must correspond exactly to 18mm.

For the Portofino IW3513-35, straps in natural alligator (dark brown or black) are recommended for those who wish to maintain authentic dress watch character. Alternatively, vegetable-tanned calf leather for a more informal style, NATO in dense nylon for professional contexts, or technical rubber for maritime environments. The choice depends on the context of use and personal aesthetic preferences.

Changing the strap on the Portofino IW3513-35 is accomplished by removing the lug pins. Use a dedicated tool (spring bar tool) or consult a professional watchmaker. Insert the tip of the tool into the small hole beneath the lug, gently compress the internal spring and slide the pin downwards. Repeat the operation for both sides, then apply the new 18mm strap by aligning the pins to the lugs.

Yes, quality aftermarket straps compatible with the IWC Portofino IW3513-35 exist, provided they respect the 18mm lug width specification. MilanoStraps offers a dedicated collection of 18mm straps, crafted in alligator, shell cordovan, vegetable-tanned calf, NATO and technical rubber, customisable in length and stitching thread. All are subjected to rigorous quality control before shipment.

The lifespan of a leather strap depends on the material and usage. A quality artisanal alligator strap, worn daily under normal conditions, lasts approximately 3-5 years before replacement is required. Vegetable-tanned calf leather has similar longevity but develops patina more rapidly. In humid environments or those exposed to intense perspiration, lifespan is reduced. MilanoStraps offers an 18-month warranty on straps and support for buckle replacement or minor repairs during the warranty period.