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

The lug width of the Rolex Datejust 31 ref. 178240-0035 is 16mm. This measurement is specific to the 31mm case of this family and should be verified using a digital calliper placed between the lugs, flush against the case, to obtain the precise internal measurement.

For the Datejust 31 in Oystersteel, a square-grain alligator strap with vegetable tanning is the most coherent choice given the watch's formal character. For everyday wear, hand-finished smooth calfskin develops an authentic patina over time. A brushed steel deployant clasp completes the pairing with metallic consistency matching the case finish.

To replace the strap on the Datejust 31, you must remove the spring bars securing the strap to the case lugs. Use a fine-tipped spring bar tool to compress the bar within the lug channel. It is advisable to work on a soft surface to avoid scratching the case or bracelet lugs during the operation.

Yes, high-quality aftermarket straps are available for the 16mm lug width of the Datejust 31. Milano Straps offers a curated selection of handcrafted straps in alligator, calfskin, shell cordovan and technical materials specifically for this size, produced with bespoke craftsmanship by the Casati Milano atelier.

The lifespan of a leather strap depends on tanning quality and daily use. A premium vegetable-tanned alligator strap, with proper care — leather conditioner and rotation with other straps — can last between three and seven years while maintaining structural integrity. Prolonged exposure to water and perspiration accelerates deterioration, particularly at the flex points.