Rolex
Datejust 31 178248-0044— lug 16mm

The Rolex Datejust 31 ref. 178248-0044 has a lug width of 16mm, measured between the lugs at the lower part of the case. This dimension is standard across the entire Datejust 31 family and should be verified with a digital calliper before purchasing an aftermarket strap.

For an 18-carat yellow gold case such as that of the Datejust 31, an alligator strap in vegetable-tanned leather represents the most coherent pairing for a timepiece of this calibre. The belly grain of alligator leather contrasts elegantly with the polished gold surface. Alternatively, shell cordovan develops a luminous patina that complements the precious metal. The buckle or deployant clasp should be in yellow gold to maintain metallic consistency.

Replacing the strap on the Datejust 31 requires a dedicated spring bar tool or, preferably, a professional pin tool. Original Rolex spring bars have a specific diameter: it is advisable to replace them with high-quality steel spring bars of 1.8mm diameter. The operation should be performed on a protected surface to avoid scratching the yellow gold case. If in any doubt, it is preferable to entrust the work to a watchmaker or the Casati Milano atelier.

Yes, high-quality aftermarket straps compatible with the Datejust 31 16mm lug width do exist. The handcrafted straps produced by Casati Milano for milanostraps.it are calibrated to the specific curvature of Rolex lugs, with shaped ends for a precise fit. It is essential to verify that the manufacturer explicitly declares compatibility with the 16mm lug width and that the strap ends follow the curvature of the Datejust lugs.

The lifespan of a leather strap depends on the quality of the tanning, the thickness of the hide, and conditions of use. A high-quality vegetable-tanned alligator strap, used carefully and kept away from prolonged contact with water and perspiration, can last between 3 and 7 years whilst maintaining a dignified patina. Shell cordovan offers superior durability thanks to its dense fibre structure. The use of a protective cream for exotic leathers and rotation between multiple straps significantly extends the life of the piece.