Strap for Portofino Automatic Stainless Steel / Black - Breguet / Strap

The lug width of the Portofino IW3513-42 is exactly 18 millimetres. This measurement is set at the factory and is critical for correct strap installation. A smaller strap (16mm) would create unwanted lateral play, while a larger one (20mm) would not mount correctly. The mounting tolerance on this compact case is strictly defined.

The ideal strap for the Portofino IW3513-42 must respect the compact proportions of the case. Vegetable-tanned alligator is the most refined solution, as its natural grain remains proportionate. Shell cordovan represents an exceptional alternative for daily wear, with superior durability. Vegetable-tanned calf leather offers elegance with ease of maintenance. For summer use, black rubber with a deployante keeps the case's visual lightness intact.

Strap changes require a dedicated spring bar tool. Position the watch case-up, locate the lower lug and use the spring bar tool to push the retention bar laterally, creating the necessary clearance for extraction. Repeat for the upper lug. Insert the new strap by aligning the holes with the bars, then press until they click into place. Avoid forcing the operation to prevent damage to the lug seat.

Yes, quality aftermarket straps made from premium leather—such as alligator, cordovan, or calf—are fully compatible with the Portofino IW3513-42, provided they respect the 18mm lug width. Artisanal straps with vegetable tanning harmonise naturally with this watch's classical style, often offering superior leather and customisation options compared to factory alternatives. Always verify that the spring bars are correctly sized for the lug seat.

A quality leather strap with vegetable tanning typically lasts 3–5 years under moderate daily use. Shell cordovan exceeds this duration, reaching 5–7 years due to its dense fibre structure. Alligator has a comparable lifespan to calf leather when properly maintained. Longevity depends on UV exposure, humidity, and frequency of wear. Regular maintenance with specialist leather creams significantly extends strap lifespan.