Rolex
Datejust 31 278384RBR-0039— lug 16mm

The Rolex Datejust 31 278384RBR-0039 has a lug width of 16mm. This measurement should be taken with a digital calliper between the two lugs of the case, at the point where the strap inserts. It is specific to the 31mm Datejust case and is not interchangeable with 17mm or 18mm straps without compromising the fit and aesthetics of the pairing.

For the Datejust 31 278384RBR-0039 in Oystersteel and white gold with a diamond-set bezel, a polished alligator strap is the most coherent choice: the natural scale texture complements the refinement of the bezel. Alternatively, vegetable-tanned smooth calf in neutral tones (ivory, sand, slate grey) or shell cordovan offer a more understated, bespoke character. For casual wear, a 16mm vulcanised rubber strap maintains the correct visual proportions.

To replace the strap on the Datejust 31, a fine-tipped spring bar tool is required. Insert the tip into the small slot inside each lug, compress the spring bar and slide the strap free. Care must be taken not to scratch the Oystersteel case or the white gold components. It is advisable to have the operation carried out by a watchmaker or a specialist atelier such as Casati Milano to avoid irreversible damage.

Yes. The Datejust 31 278384RBR-0039 has 16mm lugs, a size for which high-quality aftermarket straps are readily available. The milanostraps.it selection dedicated to 16mm straps includes options in alligator, calf leather, shell cordovan and rubber, all produced with buckles and deployant clasps compatible with the Rolex standard. Premium aftermarket straps are often finished with vegetable-tanned leathers and hand-stitched edges, offering greater personalisation than factory options.

The lifespan of a leather strap depends on the quality of the tanning, the leather thickness and conditions of use. A first-quality alligator or shell cordovan strap, worn daily but kept away from prolonged exposure to water and perspiration, will typically last between three and five years before showing structural wear. Vegetable-tanned calf, while more affordable, develops an attractive patina but deteriorates more quickly in humid conditions. Casati Milano offers an 18-month guarantee against manufacturing defects on all bespoke straps.