IWC · Portofino

Strap for IWC Portofino IW3731-02

The 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

18mm
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Lug width18 mm
Case diameter35 mm
ReferenceIW3731-02 (aka: IW373102)
FamilyPortofino
MovementJaeger-LeCoultre caliber 631 Hours, Minutes, Small seconds | Date | Chronograph
Year1988 - 1998
CaseYellow Gold

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Standard spring bar · length 18 mm · Ø 1.8 mm double flange · industry standard, no brand part number

Portofino Chronograph MecaQuartz Yellow Gold / White / Alligator — watch

What I'm asked about the IWC Portofino IW3731-02

What strap size does the IWC Portofino IW3731-02 take?

The IWC Portofino IW3731-02 needs 18 mm between the lugs, usually 16 mm at the buckle. It's the size I've been fitting on it for years.

Can the strap on the IWC Portofino IW3731-02 be changed?

Yes. It has spring bars between the lugs: with the right tool the strap comes off in a minute. If you'd rather not risk a scratch, I do it in the workshop.

Can I put a leather strap on the IWC Portofino IW3731-02?

Yes, in 18 mm leather. On a 35 mm chronograph I like box calf: it holds its shape and carries a substantial case.

Which strap do you recommend for the IWC Portofino IW3731-02?

A 18 mm box calf. You'll find it ready in the 18 mm collection. If you'd rather have something built on your wrist, the Casati atelier.

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

Bespoke straps for IWC, in the atelier or by video call: casatimilano.com