Strap for Datejust 31 Yellow Gold Diamond / President / MOP Roman

The Rolex Datejust 31 reference 178158-0059 has a lug width of 16mm. This measurement is standard across the entire Datejust 31 range and must be matched precisely when selecting a replacement strap: a 15mm or 17mm attachment is incompatible and will compromise both security and aesthetics.

On a 31mm yellow gold 18-carat case, an alligator strap with vegetable tanning represents the highest technical and stylistic reference. The regular grain of the belly or flank interacts with the metal surface without competing with it. Alternatively, box calf in a matte finish offers understated formal versatility, whilst shell cordovan develops an organic patina over time that becomes uniquely personal. A deployant clasp or buckle in yellow gold 18 carats ensures full coherence with the case material.

To replace the strap on a Datejust 31, the spring bars connecting the original bracelet to the case lugs must be removed. A dedicated spring bar tool or a fine flat-head screwdriver is inserted into the small hole on the side of the lug to compress and release the spring bar. Caution: yellow gold lugs are more susceptible to scratching than steel; always use tools with plastic-coated tips or protective covers to avoid damage to the case.

Yes. The aftermarket offers a wide selection of straps with a 16mm attachment compatible with the Datejust 31. On milanostraps.it, handcrafted straps in alligator, calf, shell cordovan and NATO are available, all produced with an exact 16mm lug width to fit this reference. Casati Milano bespoke straps are made to the precise millimetre specifications of each individual watch.

The lifespan of a leather strap depends on the material, maintenance, and daily use. A quality vegetable-tanned alligator strap, with regular conditioning and protection from prolonged moisture, typically lasts between 2 and 5 years of daily wear. Calf leather offers comparable durability. Shell cordovan, owing to the dense fibre structure of the horse's rump muscle, is considerably more resistant to wear and tends to improve aesthetically over time. Casati Milano provides an 18-month guarantee on manufacturing defects on all straps.