Rolex
Day-Date 40 228396TBR-0031— lug 20mm

The lug width of the Rolex Day-Date 40 ref. 228396TBR-0031 is 20 mm. This measurement is standardised across the entire Day-Date 40 line and should be taken at the inner seat of the lug using a precision calliper, perpendicular to the case axis.

For a platinum 950 case with a diamond-set bezel, a smooth alligator strap with natural belly texture is the most technically coherent choice. Shell cordovan is an equally refined alternative, as its slightly waxy surface interacts directly with the metallic reflections of the platinum case. A deployant clasp is strongly recommended to preserve the strap's structural integrity over time.

The strap on a Rolex Day-Date 40 is removed via the spring bars housed in the 20 mm lugs. A fine-tipped spring bar tool with a rubber-coated tip is recommended to avoid scratching the platinum case. For fitting a bespoke artisan strap, it is advisable to rely on a specialist professional or a dedicated atelier such as Casati Milano.

Yes. Compatible aftermarket straps must feature a 20 mm lug width, a straight end, and a maximum thickness of approximately 3.5 mm to avoid interference with the bezel. Milanostraps.it offers a curated selection of Italian-made artisan straps in 20 mm, fully compatible with this reference and customisable in terms of material and colour.

The lifespan of a leather strap depends on material quality and maintenance. A genuine alligator or shell cordovan strap, vegetable-tanned and wax-burnished along the edges, can last between 3 and 6 years with regular use. Prolonged exposure to water and perspiration should be avoided, and periodic application of a dedicated leather conditioner is recommended.