Strap for Datejust 31 Stainless Steel Diamond / Jubilee / Pink - Roman

The lug width of the Rolex Datejust 31 178384-0009 is 16 millimetres. This dimension is specific to the 31mm case models and differs from the Datejust 36 (20mm) and 41 (21mm). The measurement should be verified with a digital calliper, inserting the tip perpendicularly between the case lugs.

For the 178384-0009 reference in steel and white gold, we recommend pearl grey alligator, vegetable-tanned calf in cognac, or cordovan in deep burgundy. Alligator complements the fluted bezel; vegetable-tanned calf develops a patina that ages beautifully. The choice depends on daily use and the aesthetic contrast desired between the two-tone case and leather.

The strap is changed by removing the spring bars using a dedicated tool. Position the tool in the small holes beside each spring bar and apply gentle downward pressure, sliding the old strap away. Repeat with the new strap, ensuring the spring bars click securely into place. If unfamiliar with the procedure, Casati Milano performs strap changes free of charge in the atelier.

Yes, 16-millimetre aftermarket straps are completely compatible with the Datejust 31 178384-0009. Milano Straps supplies artisanal straps manufactured to the same standards as Swiss producers, available in vegetable-tanned leather, alligator, cordovan and rubber. Each strap is measured with precision to ensure perfect fit and durability over time.

Durability depends on material and use. A vegetable-tanned calf strap lasts 3–5 years with daily wear; alligator can exceed 7–8 years thanks to its more robust structure. Vulcanised rubber exceeds 10 years. With regular maintenance (gentle cleaning, proper drying), patina improves and wear slows. Casati Milano offers an 18-month warranty against manufacturing defects.