Rolex · Day-Date 40

Strap for Day-Date 40 Yellow Gold - Baguette / Silver

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
Reference228398tbr-0005
FamilyDay-Date 40
MovementRolex caliber 3255 hours, minutes, seconds | date, day | chronometer
Year2015
CaseYellow 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 228398tbr-0005

Selected for the 20 mm lug width · workshop selection

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The Day-Date 40 228398tbr-0005, seen from the bench

The Day-Date was introduced in 1955 as the first automatic wristwatch with simultaneous day and date indication. It is equipped with the caliber 3255 automatic movement with official chronometer certification and display of hours, minutes, seconds, date and day of the week. The case features 20mm lugs and a movement with a power reserve of around 70 hours.

Frequently asked questions

What is the lug width of the Rolex Day-Date 40 228398tbr-0005?

The Rolex Day-Date 40 reference 228398tbr-0005 has a lug width of 20 mm. This measurement should be taken with a digital calliper at the narrowest point between the two lugs, excluding any lateral curvature. The slightly arched geometry of Rolex lugs makes it advisable to use straps with a pre-curved underside for a clean, seamless transition between case and strap.

What is the best strap for the Rolex Day-Date 40 228398tbr-0005 in yellow gold?

For the yellow gold Day-Date 40, a vegetable-tanned alligator strap in tobacco or cognac tones is the most coherent choice: the hornback or caïman texture complements the case without competing with the dial. Alternatively, black box calf leather offers sharp formal contrast, while shell cordovan brings a natural lustre of exceptional character. A yellow gold deployant clasp completes the pairing with full material consistency.

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

The strap on the Rolex Day-Date 40 is removed using a springbar tool inserted into the lug groove to compress the spring bars. Care must be taken to avoid scratching the 18-carat yellow gold case: place the watch on a protective cushion and use a soft-tipped tool. To fit the new strap, reverse the procedure, ensuring the spring bars are fully seated in both lug holes before applying tension.

Are there aftermarket straps compatible with the Rolex Day-Date 40 228398tbr-0005?

Yes. The Day-Date 40 with its 20 mm lug width is compatible with a wide range of quality aftermarket straps. Milano Straps and Casati Milano craft bespoke straps specifically for this geometry, featuring a pre-curved underside to match the Rolex lug profile. Always verify that the lug end measures exactly 20 mm and that the buckle or deployant is proportionate to the 40 mm case.

How long does a leather strap last on a Rolex Day-Date 40?

The lifespan of a leather strap depends on the material and frequency of wear. A quality vegetable-tanned alligator strap, maintained regularly with a neutral leather conditioner, will retain its structural and aesthetic integrity for 3 to 5 years of daily use. Shell cordovan, owing to its dense fibre structure, tends to last longer and develops a patina that improves with age. Box calf is slightly more sensitive to moisture. The Casati Milano 18-month guarantee covers manufacturing defects.

The next step

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