Strap for Datejust 31 Stainless Steel / Jubilee / Black - Roman

The lug width is 16mm. This dimension corresponds to the spacing between the two spring bar attachment points on the case. To verify, measure the gap between the two pins using a millimetre ruler. The 16mm lug width is the proportional standard for Datejust models in this case diameter category, ensuring aesthetic balance between the 31mm dial and strap underneath.

Alligator remains the most elegant and versatile choice: its natural geometric texture and suppleness confer inherent dignity. Round-grain calf leather appeals to those seeking uniformity of grain and patina development over time. Shell cordovan represents an extraordinary balance between durability and aesthetic patina evolution. For casual contexts, a canvas NATO in English weave transforms the watch into a statement of measured ease. Choice depends on usage context and personal preference regarding tactile evolution.

The procedure requires extraction of the two spring bars using a dedicated tool called a spring bar tool. Position the watch on a soft surface, locate the two lateral attachment points, gently push the spring bar inward using the tool, and slide the existing strap away from the pins. Insert the new strap in the same sequence, ensuring the pins are fully seated in the attachment points. If you lack the tool, a professional watchmaker completes the operation in under five minutes. Avoid sudden movements to prevent case scratching.

Absolutely. All high-quality artisanal straps with 16mm lug width are entirely compatible with the Datejust 31 278240-0002. The critical factor is verifying that the width is precisely 16mm: even minor deviation could cause imperfect seating in the spring bar pins. Reputable manufacturers such as Casati Milano, as well as certified alligator and shell cordovan producers, guarantee millimetre-level precision tolerances. An aftermarket strap preserves the original watch's value while enabling broader aesthetic exploration.

Longevity depends on leather quality, usage patterns, and maintenance. A high-quality alligator or shell cordovan strap, with moderate daily use and proper care (avoid prolonged moisture exposure, indirect sunlight), lasts 4–6 years without functional or aesthetic compromise. Round-grain calf exhibits wear signs more rapidly but develops a fascinating patina. Canvas NATO lasts indefinitely, being resistant to cracking. To maximise longevity, store the strap in a dry environment, avoid prolonged contact with salt perspiration, and consider rotating multiple straps seasonally.