Rolex
Datejust 31 178248-0070— lug 16mm

The Rolex Datejust 31 ref. 178248-0070 has a standard lug width of 16mm. This measurement should be taken with a digital calliper positioned between the inner walls of the lugs — not the outer edges, which would yield a larger figure. Any replacement strap must feature a 16mm end width to ensure a precise fit without lateral play.

For an 18-carat yellow gold case such as that of the Datejust 31 ref. 178248-0070, a vegetable-tanned alligator strap is technically the most coherent pairing. The regular grain of the alligator belly and its three-dimensional texture complement the craftsmanship of the gold case. Alternatively, a box-grain calf leather strap develops a fine patina over time and offers everyday versatility. Shell cordovan, with its dense, warm-toned surface, enhances the gold tones particularly well in natural light.

To replace the strap on a Datejust 31, a fine-tipped spring bar tool is required. The lugs on the Datejust 31 are short and slightly downward-curved, so working on a watch cushion is advisable to protect the yellow gold case from scratches. Compress the spring bar on one side to release it from the lug, remove the strap, and insert the new one in reverse order. If in doubt, a watchmaker or the Casati Milano service team can perform the operation without risk to the case.

Yes, high-quality aftermarket straps are fully compatible with the Datejust 31 ref. 178248-0070. The key parameters are the 16mm lug width and the curved end profile required to fit the geometry of the Datejust 31 lugs. Handcrafted straps produced by Casati Milano for milanostraps.it are developed to these exact specifications and can be made to order in the material and colour of your choice, with either a tang buckle or a deployant clasp.

The lifespan of a leather strap depends on the material, frequency of wear, and maintenance. A high-quality vegetable-tanned alligator strap, rotated with other straps and kept away from prolonged moisture exposure, can last between 3 and 5 years while retaining structural integrity and aesthetic appeal. Calf leather tends to develop a patina more rapidly and typically requires replacement after 2 to 3 years of regular wear. Shell cordovan, owing to the density of its fibres, is among the most durable leathers and can exceed 5 years with minimal care.