Rolex
Datejust 31 278273-0029— lug 16mm

The Rolex Datejust 31 ref. 278273-0029 has a lug width of 16mm. This measurement can be verified using a digital calliper, measuring the internal distance between the two lugs at the lower part of the case. This specific dimension requires aftermarket straps purpose-made for the 16mm format.

For the Datejust 31 in yellow Rolesor, an alligator strap with vegetable tanning in dark brown or cognac is the most coherent choice given the model's formal character. For a more relaxed daily use, vegetable-tanned calfskin develops an authentic patina over time. A deployant clasp in steel or yellow gold significantly improves wrist fit and extends strap life.

To replace the strap or bracelet on the Datejust 31, the spring bars must be removed using a fine-tipped spring bar tool. Rolex spring bars feature a side slot for compression. Insert the tool tip into the slot, compress the spring, and slide the bar out. Precision is essential to avoid scratching the case. If in doubt, consult a watchmaker or the Casati Milano atelier.

Yes. Aftermarket straps with a 16mm lug width are compatible with the Datejust 31, provided the ends are pre-curved to correctly interface with Rolex lugs. Milanostraps.it offers a curated selection of handcrafted straps in alligator, calfskin, shell cordovan and rubber specifically made for this format, with a choice of finishes and linings.

The lifespan of a leather strap depends on the material and maintenance. A quality alligator strap with vegetable tanning, periodically treated with neutral balm, can exceed 3–5 years of regular use. Calfskin has a somewhat shorter average lifespan but develops a distinctive patina. Keeping the strap away from water, excessive perspiration and direct sunlight significantly prolongs its life.