Strap for Datejust 31 Yellow Gold Domed / President / MOP

The lug width of the Rolex Datejust 31 reference 178248-0025 is 16 millimetres. This measurement indicates the distance between the two attachment pins of the case to the bracelet or strap. It is a specific dimension for this model: the Datejust 36 uses 20 mm, whilst the Day-Date President employs 18 mm. To verify with certainty, measure the distance between the two pins protruding from the case, or remove the original bracelet and check the engraving inside the case.

For the Datejust 31 178248-0025 in yellow gold, we recommend straps in natural alligator or vegetable-tanned calf leather. Alligator respects the sobriety of the material with its fine-scaled texture and the patina that develops naturally over time, creating visual harmony with the lustre of gold without generating excessive contrast. Calf leather absorbs moisture better and develops its own authentic patina. Recommended colours: dark brown, aged cognac, burgundy or black depending on the dial finish and your daily use.

To change the strap, you must remove the two attachment pins from the case. Using a dedicated tool (spring bar tool), push the small metal pin downward to release it and slide out the existing bracelet or strap. Insert the new 16 mm strap into the two seats on the case and reinsert the pins until you hear an audible click. If you are unsure of this procedure, entrust the work to a professional watchmaker or the Casati Milano service, which performs the change with care and precision during a bespoke personalisation session.

Yes, it is possible to use an aftermarket strap compatible with 16 mm lug width. However, quality and compatibility vary considerably between manufacturers. High-quality alligator or calf leather straps, crafted by specialised artisans such as Casati Milano, maintain the aesthetics and value of your original Rolex, avoiding damage to the case from poor manufacturing tolerances. Avoid generic or inferior-quality straps: a Rolex deserves a strap built with equal artisanal dedication.

The lifespan of a leather strap depends on daily use, ambient humidity and maintenance. A high-quality alligator strap, crafted with vegetable tanning, typically lasts 3–5 years of intense daily use, developing increasingly rich patina. Vegetable-tanned calf lasts similarly, but absorbs more moisture and may require periodic conditioning. A cotton NATO strap lasts longer if kept dry, potentially exceeding 7 years. Casati Milano's warranty covers manufacturing defects for 18 months. Durability also depends on care: protecting the strap from prolonged contact with heavy perspiration and extreme humidity significantly extends its useful life.