Rolex
Datejust 31 178243-0049— lug 16mm

The Rolex Datejust 31 reference 178243-0049 has a lug width of 16mm. This is a non-standard measurement in mass-produced strap manufacturing, making it necessary to source from specialist craftsmen or dedicated suppliers. To measure it independently, use a digital calliper placed internally between the two lugs at the point of contact with the case.

For the Datejust 31 in yellow Rolesor with a mother-of-pearl dial, the most suitable straps are vegetable-tanned alligator (in burgundy, cognac or midnight blue) or smooth box-calf leather. Shell cordovan is a compelling alternative with remarkable character. A deployant clasp in yellow gold or brushed steel completes the pairing with both aesthetic coherence and daily wearability.

Changing the strap on the Datejust 31 requires a spring bar tool to remove the spring bars that secure the strap to the case lugs. This is a delicate operation and, to preserve the finish of the steel and yellow gold case, it is advisable to entrust it to a watchmaker or specialist atelier. Casati Milano offers this service by appointment.

Yes. Milanostraps.it offers handcrafted aftermarket straps specifically made for 16mm lug widths, compatible with the Datejust 31. Each strap is produced using selected materials — alligator, calf leather, shell cordovan — and can be customised in heel curve, colour and clasp type, ensuring an optimal fit on original Rolex lugs.

The lifespan of a leather strap depends on the material, frequency of use and exposure to moisture and perspiration. A quality alligator strap, used in rotation and stored properly, typically lasts 3 to 5 years while retaining its structural and aesthetic integrity. Shell cordovan tends to last even longer, developing a distinctive patina over time. Casati Milano provides an 18-month guarantee against manufacturing defects on all its straps.