IWC · Portofino
Strap for Portofino Chronograph MecaQuartz Yellow Gold / White / Alligator
Takes 18 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
The Portofino IW3731-02 (aka: IW373102), seen from the bench
Frequently asked questions
What is the exact lug width of the IWC Portofino IW3731-02?
The lug width is 18 millimetres. This measurement is specific to the 35 millimetre Portofino and ensures balanced proportions between case and strap. Always verify by measuring the case lugs directly before purchasing an aftermarket strap.
Which strap is most suitable for the IWC Portofino in yellow gold?
Alligator leather in brown or cognac tones is the natural choice, as the warm colouration perfectly complements yellow gold. Burgundy shell cordovan represents an elegant and bold alternative. For versatility, vegetable-tanned calfskin in mid-tones also delivers excellent results.
How do I change the strap on the Portofino IW3731-02?
The strap is changed by withdrawing the spring bars from the lugs. Use a dedicated watch tool (spring bar spreader) or a small flat-head screwdriver. Gently lift the cylindrical pin, slide out the old strap and insert the new one, ensuring the pin sits completely in the lug housing.
Is an 18mm aftermarket strap compatible with my Portofino?
Yes, provided it is specified for 18 millimetre lug width and your timepiece is a 35 millimetre Portofino. However, verify compatibility by measuring the lugs directly. Quality certified straps with appropriate buckles guarantee safety and longevity.
How long does a leather strap last on a Portofino?
A quality leather strap, with regular maintenance, lasts between 3 and 5 years depending on usage and tanning method. Alligator and shell cordovan are more durable; calfskin requires greater care. Standard warranty is 18 months; repairs or replacements require professional servicing.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only