Rolex
Datejust 31 278384RBR-0037— lug 16mm

The lug width of the Rolex Datejust 31 reference 278384RBR-0037 is 16mm. This measurement refers to the internal distance between the two lugs of the case and is the specification required when selecting a compatible strap. It can be verified using a digital calliper placed between the lugs in contact with the case.

For a white gold case with a diamond-set bezel such as the Datejust 31 278384RBR-0037, a vegetable-tanned alligator strap is the most coherent choice: the grain texture engages visually with the worked surface of the bezel and develops a patina over time. Shell cordovan is the alternative for those who prefer a compact, near-burnished surface. In both cases, a white gold buckle or a steel deployant clasp completes the pairing without metallic discontinuity.

To replace the strap on a Rolex Datejust 31, the spring bars connecting the bracelet to the case lugs must be removed. This requires a dedicated spring bar tool with a blunt tip, inserted into the spring bar slot, taking care to avoid scratching the white gold case. It is advisable to work on a soft surface and, if in doubt, to entrust the operation to a watchmaker or specialist atelier.

Yes, aftermarket straps compatible with the Rolex Datejust 31 are available in 16mm lug width. It is essential that the strap is cut precisely to 16mm without approximate tolerances, to avoid lateral play or fitting difficulties. Milano Straps offers a selection of 16mm straps in alligator, calf leather and cordovan, handcrafted and also available bespoke through the Casati Milano atelier.

The lifespan of a leather strap depends on the material, frequency of use and exposure to perspiration and moisture. A quality alligator strap with vegetable tanning and careful finishing can last between 2 and 5 years with regular use. Shell cordovan tends to offer greater abrasion resistance. Rotating between several straps and storing them away from heat sources will significantly extend the leather's service life.