Rolex
Datejust 31 178159-0071— lug 16mm

The Rolex Datejust 31 178159-0071 has a lug width of 16mm. This measurement is specific to the 31mm case size and requires straps made precisely for this attachment: it is not interchangeable with the standard 18mm or 20mm widths common to other models within the Datejust family.

For an 18-carat white gold case, a vegetable-tanned alligator strap is the most formally coherent choice: the grain texture complements the polished case surface without competing with it. Box-calf leather is an excellent option for daily wear, whilst shell cordovan offers superior resistance to deformation over time. A deployant clasp in white gold ensures consistent metal matching with the case.

The strap on the Datejust 31 178159-0071 is secured to the lugs via 16mm spring bars. To replace it, use a fine-tipped spring bar tool: compress the bar laterally within the lug, remove the strap and fit the new one. Care should be taken not to scratch the white gold case; if in doubt, consult a watchmaker or the Casati Milano atelier.

Yes. Aftermarket straps for the Datejust 31 178159-0071 must conform to a 16mm attachment width. On milanostraps.it, handcrafted options in alligator, box-calf and shell cordovan are available, made specifically for this lug width. It is important to verify that the strap's thickness at the attachment point is compatible with the case profile, which on the 31mm is particularly slim.

The lifespan of a leather strap on a Datejust 31 depends on the type of leather, the tanning method and pattern of use. A quality vegetable-tanned alligator strap, properly rotated and kept away from prolonged moisture, will retain structural and aesthetic integrity for 3–5 years. Box-calf has an average lifespan of 2–3 years with daily use. Shell cordovan is the most durable owing to its dense fibre structure and can exceed 5 years whilst retaining its lustre and shape. Casati Milano offers an 18-month guarantee against manufacturing defects on all straps.