Rolex
Datejust 31 178313-0056— lug 16mm

The Rolex Datejust 31 ref. 178313-0056 has a nominal lug width of 16mm. Before purchasing an aftermarket strap, it is advisable to verify the actual measurement using a digital calliper: manufacturing tolerances may bring the real value between 15.8 and 16.2mm. The milanostraps.it straps for 16mm lug width are designed to this specification and fit without modification.

For the Datejust 31 in stainless steel and yellow gold, a polished alligator strap in bordeaux or cognac is the most coherent choice for the watch's formal character. Shell cordovan in tobacco brown or midnight blue offers a refined alternative with a natural patina development over time. For less formal contexts, vegetable-tanned calf leather provides comfort and durability. A butterfly deployant clasp is recommended to reduce stress on the strap keeper.

To replace the strap on the Datejust 31, you need a spring bar tool or a 1.0–1.2mm flat-head precision screwdriver. Insert the tip into the lateral notch of the lug, compress the spring bar and slide it out. Care must be taken to avoid scratching the Oystersteel lugs. Alternatively, Casati Milano can perform the swap in the atelier by appointment.

Yes. Aftermarket straps compatible with the Datejust 31 must have a 16mm lug width and, ideally, slightly curved ends to follow the case profile. milanostraps.it offers a selection of handcrafted straps in alligator, shell cordovan, calf leather, NATO and rubber, made specifically for the 16mm lug, with stainless steel spring bars included.

The lifespan of a leather strap depends on the material, frequency of use and exposure to perspiration and moisture. A quality alligator strap, with daily alternated use, typically lasts 2–4 years. Shell cordovan, due to its dense fibre structure, can exceed 4–5 years while developing a distinguished patina. Vegetable-tanned calf leather straps have an average life of 1–3 years. Rotating between multiple straps significantly extends the life of each one.