Rolex
Datejust 31 178248-0056— lug 16mm

The Rolex Datejust 31 ref. 178248-0056 features a lug width of 16mm, measured internally between the two lugs at the strap attachment point. This measurement is specific to the 31mm case size and differs from the 20mm of the Datejust 41 and the 13mm of the Lady-Datejust 28. A digital calliper is recommended for accurate measurement.

For an 18-carat yellow gold case, a vegetable-tanned alligator strap with belly grain is the most coherent choice: the symmetrical scales complement the metallic reflections without competing with them. Box-grain calf leather is preferable for intensive daily wear, whilst shell cordovan develops a distinctive patina over time with superior longevity. The most effective colour pairings are burgundy, midnight blue and forest green.

Strap replacement requires a spring bar tool (a forked-tip lever) to remove the spring bars securing the strap to the lugs. Insert the tip into the lateral notch of the lug, compress the spring bar and slide the strap out. The Datejust 31 uses standard 1.5mm diameter spring bars. The operation does not require Rolex tools, but it is advisable to work on a soft surface to avoid scratching the gold case.

Yes. The Datejust 31 uses standard 16mm lugs with conventional spring bars, making it compatible with any aftermarket strap in 16mm with a straight end. Milano Straps offers handcrafted straps in alligator, calf leather, shell cordovan and rubber specifically selected for this reference, available in the dedicated 16mm lug width collection.

Longevity depends on the material and conditions of use. A quality vegetable-tanned calf leather strap typically lasts 2–4 years with daily wear, developing a characteristic patina. Vegetable-tanned alligator can exceed 5 years when kept away from perspiration and water. Shell cordovan, owing to its dense fibrous structure, offers greater longevity than both. All Casati Milano straps carry an 18-month guarantee against manufacturing defects.