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

The lug width (ansa measurement) of the Rolex Datejust 31 reference 178278-0115 is 16 millimetres. This dimension, measured between the inner lug attachments on the case, requires specifically tailored straps. It is not a standardised width in commercial markets, which is why Casati Milano manufactures each strap bespoke to ensure perfect integration with the yellow gold case.

For this yellow gold model, we recommend alligator with vegetable tanning or vintage calf leather. Alligator delivers formal elegance with consistent texture; vintage calf develops a caramel patina over time, creating remarkable synergy with the case's natural ageing. Shell cordovan is ideal for those seeking a strap with structured body and natural lustre. All these materials harmonise beautifully with the compact case proportions.

The strap is changed using a spring bar removal tool. The procedure requires precision to avoid scratches on the yellow gold case. If you lack experience, we recommend having an authorised Rolex retailer or specialised watchmaker perform the operation. With Casati Milano, we can guide you step-by-step via WhatsApp throughout the entire process.

Yes, with critical precision: only straps engineered specifically for the 16-millimetre lug width are compatible. Many aftermarket straps are manufactured for 18mm or 20mm widths, creating visible misalignments. Bespoke straps crafted by Casati Milano for 16mm sizing guarantee perfect fit and structural longevity.

A high-quality leather strap—alligator, calf, or shell cordovan—typically lasts 4-6 years with proper maintenance (periodic cleaning, protection from excessive moisture). Longevity depends on frequency of wear, climate exposure, and care routines. Casati Milano straps include an 18-month manufacturer's warranty and personalised maintenance guidance, significantly extending the useful life of your strap.