Rolex
Day-Date 36 118139-0026— lug 20mm

The lug width of the Rolex Day-Date 36 reference 118139-0026 is 20 mm. This measurement is taken between the two lugs at the point where the strap attaches to the case, and it is consistent across all production examples of this white gold 36 mm reference.

For the Day-Date 36 in white gold, a belly-cut alligator strap — in gloss black or tobacco brown — is the canonical choice, as the scale texture complements the case finishing. Shell cordovan offers a dense, structured patina well suited to extended formal wear. In all cases, the 20 mm strap must feature curved ends to conform correctly to the geometry of the integrated lugs.

Changing the strap on a Rolex Day-Date 36 requires a fine-tipped springbar tool to compress the springbars housed within the integrated lugs. It is advisable to work on a soft watchmaker's mat to protect the bezel and dial. If you are not experienced with this procedure, we recommend entrusting the work to a watchmaker or to Casati Milano's atelier to avoid scratching the white gold case.

Yes. Aftermarket straps compatible with the Rolex Day-Date 36 118139-0026 must conform to the 20 mm lug width and feature pre-curved ends to fit the integrated lugs correctly. Milanostraps.it offers a curated selection of handcrafted 20 mm straps in alligator, calf leather and shell cordovan, with buckle or deployant clasp options available in various metals, including white gold PVD finish.

The lifespan of a leather strap depends on the material, care and frequency of use. A quality alligator strap worn daily typically lasts between two and four years before visible wear appears on the keeper and inner lining. Shell cordovan, owing to its structural density, tends to last longer whilst developing a distinctive patina. Avoiding prolonged exposure to water and perspiration will significantly extend the strap's service life.