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 width20 mm
Case diameter40 mm
Reference228396TBR-0031
FamilyDay-Date 40
MovementRolex caliber 3255 hours, minutes, seconds | date, day | chronometer
Year2021
CasePlatinum

Recommended spring bar

Spring bars Rolex Daytona 116520 — 20mm steel

Technical match for lug width and diameter · lug 20 mm · Ø 1.5 mm · closed lugs

All Rolex spring barsOpen →

Straps for the Day-Date 40 228396TBR-0031

Selected for the 20 mm lug width · workshop selection

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The Day-Date 40 228396TBR-0031, seen from the bench

The Day-Date 40 represents the evolution of the classic Rolex wristwatch with day and date indication. It is equipped with the automatic Calibre 3255 certified chronometer, offering hour, minute, second, date and day of the week indication. The 40mm case is fitted with 20mm lugs.

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.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only