Rolex · Day-Date 40
Strap for Day-Date 40 Platinum - Baguette / Grey
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Straps for the Day-Date 40 228396TBR-0031
Selected for the 20 mm lug width · workshop selection
Matte Dark Gray Alligator Strap€195
Black Alligator Strap with Light Red Edging€149
Vintage Alligator Strap Cognac€195
Hammered Pink Strap with Ecru Stitching€98
Vintage Brown Calfskin Strap — Natural Patina€98
The Day-Date 40 228396TBR-0031, seen from the bench
Frequently asked questions
What is the lug width of the Rolex Day-Date 40 reference 228396TBR-0031?
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.
What is the best strap for the Rolex Day-Date 40 228396TBR-0031 in platinum?
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.
How do you change the strap on a Rolex Day-Date 40?
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.
Are there aftermarket straps compatible with the Rolex Day-Date 40 228396TBR-0031?
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.
How long does a leather strap last on a Rolex Day-Date 40?
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.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only

