Strap for Datejust 31 White Gold Diamond / President / MOP

The lug width of the Rolex Datejust 31 ref. 178159-0001 is 16mm. This measurement is standard for all Datejust 31 models featuring the ladies' white gold case and is incompatible with alternative lug widths (14mm, 18mm, 20mm). To verify this specification accurately, use a digital caliper positioned perpendicularly between the two internal lugs of the case.

For the white gold Datejust 31, an alligator strap is the optimal choice, particularly in dark tones (black, chocolate brown) or hues that complement the dial (grey, burgundy). Alligator offers sophisticated aesthetic contrast, develops a noble patina over time, and maintains the softness appropriate for a ladies' wrist. Valid alternatives include vegetable-tanned calf leather (which exhibits evolving patina) and shell cordovan (for those seeking tactile density and burgundy tonality). For daily wear, treated rubber or reinforced canvas NATO straps provide practicality without aesthetic compromise.

Strap replacement requires a specialised tool called a spring bar tool. Insert the flat end of the tool into the lateral hole of the case to compress the internal spring mechanism, then extract the metal bar (spring bar) connecting the old strap to the lugs. Repeat this procedure on the opposite side. Once the lugs are free, insert the new 16mm strap through the same holes, ensuring both attachments click securely into place. If you lack experience, entrust this operation to a certified watchmaker to prevent damage to the lugs.

Yes, provided the aftermarket strap has an exact 16mm lug width and is constructed from quality materials. Milano Straps specialises in bespoke, handcrafted straps utilising noble leathers (alligator, vegetable-tanned calf, shell cordovan). Each strap is supplied with an 18-month warranty covering manufacturing defects, and you may request personalised consultation at the Casati Milano atelier to select the leather type, colour, and buckle style (white gold deployante or standard) most suited to your timepiece.

The longevity of a leather strap depends on material quality, frequency of wear, and maintenance practices. A superior-grade alligator strap lasts between 4 and 7 years under moderate daily use, developing an increasingly noble patina. Vegetable-tanned calf exhibits similar durability but is more sensitive to humidity. Shell cordovan is exceptionally durable (7–10 years) yet requires periodic maintenance. Avoid prolonged exposure to water, direct sunlight, and aggressive cleaning agents. Milano Straps provides each strap with 18 months' warranty against manufacturing defects, independent of natural wear.