Rolex
Datejust 31 178243-0037— lug 16mm

The Rolex Datejust 31 reference 178243-0037 has a lug width of 16mm. This measurement must be taken internally between the two lugs using a digital calliper, and represents the correct dimension to specify when ordering a compatible aftermarket strap. Care should be taken not to confuse it with the overall case width.

For the Datejust 31 178243-0037 in Yellow Rolesor, alligator straps with vegetable tanning are the most coherent choice from a formal standpoint, as the scale grain complements the geometry of the Oyster case. Smooth calf leather offers a more understated profile, whilst vulcanised rubber is suited to sporting contexts. In all cases, the lug width must measure exactly 16mm.

Strap replacement requires the removal of the spring bars connecting the bracelet or strap to the case lugs. A dedicated flat-tip or forked spring bar tool is used for this purpose. Given the 16mm non-standard lug width, it is advisable to consult a watchmaker or carefully verify strap compatibility before proceeding independently.

Yes. Milanostraps.it offers artisan aftermarket straps produced specifically for the 16mm lug width of the Datejust 31, with shaped ends to ensure precise fitment and no lateral play. Available materials include alligator, calf leather, shell cordovan and vulcanised rubber, with bespoke customisation available through the Casati Milano atelier.

The lifespan of a leather strap depends on the material, tanning method and daily use. A quality vegetable-tanned alligator strap, properly maintained with neutral conditioners and not regularly exposed to water, will retain structural integrity and good aesthetics for 3–5 years with regular wear. Shell cordovan tends to last longer due to its densely packed fibres. The Casati Milano guarantee covers manufacturing defects for 18 months.