Rolex · Day-Date 40

Strap for Day-Date 40 White Gold - Diamond / White - Roman

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
Reference228349rbr-0039
FamilyDay-Date 40
MovementRolex caliber 3255 hours, minutes, seconds | date, day | chronometer
Year2015
CaseWhite Gold

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

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Straps for the Day-Date 40 228349rbr-0039

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Day-Date 40 228349rbr-0039, seen from the bench

The Day-Date 40 represents the evolution of the classic Rolex wristwatch with day and date indication. It features the automatic caliber 3255 with chronometer certification, providing hour, minute, second, date and day of the week indications. 40mm case with 20mm lugs.

Frequently asked questions

What is the lug width of the Rolex Day-Date 40 ref. 228349rbr-0039?

The lug width is 20mm. This measurement indicates the space between the case lugs where the strap attaches. Accurate measurement is critical: position a digital calliper perpendicular to the lug pins, excluding the case width itself. Incorrect measurement results in lateral play and compromises mounting aesthetics.

Which strap material is recommended for the Day-Date 40 228349rbr-0039?

For a white gold case with diamond bezel, black or dark brown alligator is optimal: the regular scute texture complements the elegance without visual conflict. Alternatively, superior quality vegetable-tanned calf offers developing patina and visible grain. Shell cordovan, though rarer, delivers unmatched aquascence.

How do I correctly change the strap on a Rolex Day-Date 40?

Use a spring bar removal tool to carefully extract the horizontal pins securing the strap to the case lugs. Proceed slowly to avoid scratching. Align the new strap holes with the lugs and reinsert the pins with gradual pressure until they click into place. If uncertain, entrust this operation to a qualified watchmaker.

Is a quality aftermarket strap compatible with the Day-Date 40 228349rbr-0039?

Yes, provided it is certified for 20mm lug width. Specialist suppliers like milanostraps.it offer handcrafted straps built to Rolex specifications with guaranteed dimensional tolerances. Compatibility is not compromised; construction quality differentiates reputable makers from improvised alternatives.

What is the typical lifespan of a natural leather strap on a Rolex Day-Date 40?

A quality alligator or vegetable-tanned calf strap typically lasts 3-5 years of daily wear, depending on environment (humidity, temperature, sun exposure) and maintenance. Leather ages naturally, developing patina. Annual oiling with specialist products extends functionality and preserves aesthetics.

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