Strap for Tonneau Worldtimer Stainless Steel / Silver / Bracelet

The lug width is 20 mm. This uncommon dimension represents the equilibrium between the structural robustness required by the automatic calibre and the proportional slenderness of the tonneau geometry. Accurate measurement of the lugs requires positioning a digital calliper between the internal attachment points of the spring bar: precision is fundamental to avoid incompatibility with aftermarket straps.

The choice depends on intended use and aesthetic preference. Alligator (Hermès Barenia Feuille or equivalent) represents the absolute luxury option, developing dramatic patina over time. Vegetable-tanned calf (Weinheimer, Minerva) offers conscious colour evolution over the coming years. For sporting environments, a cotton NATO strap in twill maintains elegant restraint. FKM rubber is recommended for aquatic or professional activities.

Position the watch on a soft surface (cotton cloth). Use a dedicated spring bar tool—never improvise with screwdrivers. Locate the small groove of the spring on the side opposite the crown and push gently inward: the spring retracts and permits lug extraction. Repeat from the opposite side. Install the new strap by inserting one complete lug first, then the other, ensuring both springs are properly positioned. Verify that the strap sits symmetrically relative to the case.

Yes. Milanostraps.it provides a complete selection of 20 mm straps: alligator, vegetable-tanned calf, NATO cotton, FKM rubber. Each strap is verified for compatibility with standard Oris spring bars. It is essential to confirm the lug width (20 mm) before purchase, as this dimension is specific and not interchangeable with 18 mm or 22 mm. Online selection permits colour and finish customisation.

The lifespan of a leather strap depends on construction quality and frequency of use. An artisanal alligator or vegetable-tanned calf supports 3–5 years of daily wear, with gradual loss of elasticity and micro-cracking after the third year. An industrial leather strap (polyamide-lined) lasts 12–18 months. Factors influencing durability include: direct sunlight exposure (accelerates UV degradation), frequent water contact (softens fibres), body perspiration (contains salts that erode structure). Minimal maintenance—wiping with a slightly damp cloth, immediate drying, avoiding heat sources—significantly extends strap life.