Rolex
Day-Date 36 118138-0102— lug 20mm

The lug width of the Rolex Day-Date 36 ref. 118138-0102 is precisely 20 millimetres. This measurement is determined by the internal distance between the two pins that connect the strap to the case lugs. For a 36mm case, 20mm represents the ideal proportion, ensuring accurate fitting without play and maintaining the aesthetic balance of the watch.

For the Day-Date 36 in yellow gold, alligator remains the classical choice: its regular grain enhances the lustre of gold without contrasting. A calf leather in chocolate brown or honey tones offers versatility and a patina that evolves with use. Shell cordovan, sourced from horse haunch leather, is ideal for those seeking robustness and a more pronounced texture. The choice depends on the context of use and personal preference.

Strap replacement requires a specific tool called a spring bar tool. Position the watch with the case facing downward and use the tool to compress the elastic pin inside the lug. Once released, the old strap slides away. Insert the new strap by aligning the holes with the pins and ensuring the elastic spring is properly positioned. If you prefer to avoid risk, entrust the task to a professional: Casati Milano offers this service by appointment.

Absolutely. Any strap with a 20mm lug width is compatible with the Day-Date 36 ref. 118138-0102. Artisanal straps, if constructed to high quality standards (such as those from milanostraps.it), guarantee not only mechanical compatibility but also superior aesthetics compared to worn OEM straps. The specificity of craftsmanship and materials can significantly elevate the perceived value of the watch.

The lifespan of a leather strap depends on the material, frequency of use, and care. High-quality artisanal alligator lasts 3–5 years with moderate wear; calf leather has similar longevity. Shell cordovan, being more robust, can exceed 5–7 years. Exposure to sunlight, water, and perspiration accelerates ageing. Proper storage (away from heat sources) and periodic maintenance significantly extend the strap's useful life.