Rolex
Datejust 31 278278-0017— lug 16mm

The lug width of the Rolex Datejust 31 reference 278278-0017 is 16 millimetres. This measurement is the standard for this 31mm model and is calculated from the inner distance between the case lugs. It is essential to respect this exact measurement to ensure that the strap fits correctly to the Datejust, without lateral movement or excessive tension on the passant.

For the Datejust 31 in yellow gold, alligator leather in vegetable tanning remains the most balanced choice, as it amplifies the warm tone of the metal and develops a natural patina over time. Shell cordovan, with its compactness and lustre, offers a more pronounced luxury alternative. For formal contexts, French calf with fine grain ensures elegance without excess. The choice depends on daily use and personal preference for seasonal changes.

Changing the strap on a Datejust 31 278278-0017 is done by removing the spring bars that connect the strap to the case lugs. With a specific tool (a spring bar remover), you gently push the bar from one side, freeing the strap. The new strap is then inserted in the same manner. If you do not feel confident, entrust the task to a professional watchmaker: the lugs of a Rolex deserve care during the replacement process.

Yes, you can. The Datejust 31 278278-0017 accepts aftermarket straps with a 16mm lug width. Straps made by specialised artisans, such as those in alligator, shell cordovan or calf leather, offer quality comparable to official Rolex models, often at lower cost and with greater personalisation. A bespoke strap from Casati Milano allows you to follow the manufacturing process and choose the leather directly in the atelier.

The lifespan of a leather strap depends on the material, frequency of use and level of care. Well-maintained vegetable-tanned alligator can last 5-7 years with daily wear. Shell cordovan, being more durable, can exceed 10 years. French calf with fine grain, more delicate, requires replacement every 3-4 years if subjected to intensive use. Casati Milano guarantees 18 months against manufacturing defects; beyond that period, durability depends on maintenance, climate and the wearer's habits.