Strap for Portugieser Automatic 40 Stainless Steel / Silver - Blue / Bracelet

The lug width of the IWC Portugieser IW3583-12 is 20 mm. This measurement must be taken from the inside of the first lug to the inside of the second lug. This is an uncommon size that requires straps specifically constructed for this proportion, and is not compatible with standard 18 mm or 22 mm lugs. Always verify your measurement before ordering an aftermarket strap.

Cognac or brown alligator remains the most harmonious choice for the Portugieser IW3583-12, owing to the balanced contrast with the stainless steel case. Shell cordovan from vegetable tanning is also excellent for those seeking a deep patina that evolves over time. Swiss calf leather provides elegant neutrality, whilst structured rubber is appropriate for casual daily wear, always maintaining texture and construction quality.

Strap replacement requires a specific tool: a spring bar tool. Insert the small hook beneath the spring bar (the elastic rod within the lug) and compress it slightly downward, creating enough space to extract the old strap. Insert the new strap in the same manner, ensuring the spring bar clicks into position. If you do not possess the tool, a specialist service centre such as Casati Milano can perform the change.

Yes, an aftermarket strap is entirely compatible with the IW3583-12, provided it is constructed for the 20 mm lug width. Artisanal straps from specialist suppliers (such as milanostraps) often offer quality superior to original straps, with greater material options (alligator, shell cordovan, vegetable tanning) and customisation possibilities. Always ensure that the strap ends are sized correctly for insertion into the spring bar.

The lifespan of a leather strap depends on use, material, and construction quality. High-quality artisanal alligator or shell cordovan with vegetable tanning can last 3–5 years with moderate daily wear. Standard calf leather typically lasts 2–3 years. Durability extends if the strap is worn sporadically or alternated with other solutions. Straps from Casati Milano include an 18-month warranty and can be revitalised to extend their lifespan.