Strap for Datejust 31 Yellow Gold Fluted / President / Champagne Roman

The lug width of the Rolex Datejust 31 reference 178278-0117 is 16mm. This measurement is taken with a digital calliper positioned between the two metallic lugs at the point where the strap meets the case, measuring the internal distance. This is a dimension specific to the Datejust 31 line and differs from the 20mm of the Datejust 41 or the 19mm of the Datejust 36.

For the Datejust 31 178278-0117 in 18-carat yellow gold, a vegetable-tanned alligator strap in tobacco, cognac or burgundy tones is the choice that best complements the case. The alligator belly develops a patina over time that harmonises with the warm reflections of the metal. Alternatives include polished box-calf leather for formal settings or shell cordovan for those who prefer a mirror-like surface with exceptional durability.

To replace the strap on a Rolex Datejust 31, the spring bars must be removed from the lugs using a dedicated angled-tip spring bar tool. Rolex spring bars are under high tension: it is advisable to work on a soft surface to protect the yellow gold case from scratches. If you are not experienced with high-value timepieces, it is preferable to entrust the operation to a watchmaker or the Casati Milano atelier.

Yes, there are aftermarket straps compatible with the Rolex Datejust 31 178278-0117 with a 16mm lug width. It is essential that the strap features pre-curved ends to fit correctly against the Rolex lug profile, ensuring a seamless contact without visible gaps. Milano Straps offers artisanal leather and rubber straps specifically built for this size, with customisable options for material, colour and clasp type, including a deployant clasp.

The lifespan of a leather strap on a Rolex Datejust 31 depends on the material and usage. A quality vegetable-tanned alligator strap, properly cared for and kept away from water and excessive perspiration, can last between 3 and 7 years whilst retaining its structure and patina. Calf leather typically lasts 2–4 years. Shell cordovan, owing to the density of its fibres, is the most long-lasting among traditional leathers. All Casati Milano straps carry an 18-month warranty against manufacturing defects.