Strap for Datejust 31 Yellow Gold Diamond / President / MOP Roman

The lug width (misura ansa) of the Rolex Datejust 31 178288-0025 is 16 millimetres. This dimension is specific to the 31mm version and was developed by Rolex to maintain correct visual proportions on medium-sized wrists. A strap with a different lug width (18mm or 14mm) will not fit properly on the case lugs, leaving gaps or causing misalignment. Measuring the lug width is straightforward: use a digital calliper to determine the internal distance between the two lugs.

Alligator remains the classic choice, as it combines the nobility of leather with the prestige of yellow gold. For everyday wear, vegetable-tanned calf offers evolving patina over time and superior comfort. Shell cordovan is ideal if you seek an almost mirror-like finish and enhanced protection on the lugs. For versatility and practicality, a high-density cotton NATO is valid, though it sacrifices the solemnity that precious material deserves. Your choice depends on intended use: formal (alligator, cordovan), everyday elegant (calf), rugged/beach (NATO).

Strap replacement requires specific tools: a spring bar tool and a scratch-resistant work surface. Position the watch case-up, locate the small holes on the lugs (where the spring bars sit), then use the spring bar tool to depress the spring and remove the old strap. Insert the new strap by aligning the holes with the spring bars, then push the spring into place until it clicks. We recommend entrusting this operation to a professional to avoid scratches or damage to the lugs, especially on precious cases such as yellow gold.

Yes, an aftermarket strap is compatible if the lug width is exactly 16 millimetres and the depth of the lug attachments meets the Rolex standard (1.8–2.0 millimetres). Specialist manufacturers such as Casati Milano produce 16mm straps with tight tolerances, ensuring a precise fit with no play. The aftermarket strap must feature compatible spring bars and a width that fully covers the area between the lugs without overhang. A handcrafted strap of quality ensures longevity and aesthetics consistent with the prestige of the case.

A quality leather strap typically lasts 3–5 years with daily wear and regular care. Factors such as climate (humidity accelerates deterioration), sun exposure, frequency of wear and leather quality influence longevity. Alligator and shell cordovan tend to last longer than plain calf due to derma density. Vegetable-tanned leather ages gracefully, developing patina, whilst chrome-tanned leather is more resistant but less aesthetically refined. Keeping the strap dry, avoiding prolonged sun exposure and cleaning it periodically with soft cloths extends service life significantly. A strap crafted by specialist artisans, using premium leather and precise stitching, can easily exceed 5 years.