Rolex
Datejust 31 278248-0019— lug 16mm

The Rolex Datejust 31 ref. 278248-0019 has a lug width of 16 mm. This is the internal measurement between the case lugs that determines the correct strap width for any replacement. Before purchasing an aftermarket strap, it is advisable to verify the measurement with a calliper to rule out variations caused by original bracelet components.

For an 18-carat yellow gold case measuring 31 mm in diameter, the most suitable straps are alligator leather (in cognac, bordeaux or bottle green tones) or vegetable-tanned calfskin for everyday wear. Shell cordovan is preferred for formal or tailored pairings. In all cases, the strap must measure exactly 16 mm at the lug end, with a taper between 12 and 14 mm to respect the proportions of a female wrist.

Strap replacement requires a spring bar tool or a fine-tipped screwdriver. Apply gentle leverage between the lug and the spring bar to compress the pin and release the strap. It is recommended to work on a soft surface to protect the gold case. If in doubt, entrust the operation to a watchmaker or to the Casati Milano atelier.

Yes. Any strap with a lug width of 16 mm and standard spring bars is technically compatible with the Datejust 31 278248-0019. milanostraps.it offers a curated selection of handcrafted 16 mm straps in various materials — alligator, calfskin, shell cordovan, NATO and rubber — with stitching and finishing appropriate for a Rolex timepiece in gold.

The lifespan of a leather strap depends on the material, frequency of use and environmental conditions. A high-quality alligator strap, hand-stitched and vegetable-tanned, can last between 3 and 6 years with regular wear if kept away from prolonged water exposure and excessive perspiration. Vegetable-tanned calfskin develops a patina over time but deteriorates more quickly in humid conditions. milanostraps.it offers an 18-month guarantee against manufacturing defects on all Casati Milano straps.