Rolex · Day-Date 40

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

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-0004
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-0004

Selected for the 20 mm lug width · workshop selection

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The Day-Date 40 228398tbr-0004, seen from the bench

The Rolex Day-Date 40 in yellow gold ref. 228398tbr-0004 is the contemporary evolution of an icon born in 1956, featuring a 40mm case with champagne dial and applied Arabic numerals. It houses the Caliber 3255 in-house movement with COSC chronometer certification, 3-day power reserve, and ±2 per day precision; the case measures 40mm diameter and 12mm thickness with anti-reflective sapphire crystal on both sides and 100m water resistance. The 20mm lug width is essential for proper strap compatibility without lateral play or friction.

Frequently asked questions

What is the lug width of the Rolex Day-Date 40 228398tbr-0004?

The Rolex Day-Date 40 228398tbr-0004 features a 20mm lug width. This measurement represents the internal distance between the lugs of the watch case. It is essential to verify that any aftermarket strap is manufactured at precisely 20mm to ensure perfect compatibility and a secure, rattle-free fit.

Which type of strap is best suited for the Day-Date 40 in yellow gold?

For the Day-Date 40 228398tbr-0004 in yellow gold, vegetable-tanned alligator is the most elegant choice, followed by coloured calf leather (brown, burgundy). The warm yellow gold pairs naturally with warm tones and aged patinas. For more versatile daily use, medium brown calf offers balance between formality and practicality. Red-mahogany shell cordovan creates a sophisticated and evolving aesthetic over time.

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

The strap is changed by removing the lateral spring bars using a dedicated tool or small knife, without forcing to avoid case scratches. The old strap is withdrawn and the new one inserted, ensuring the spring bars click fully into their seats. It is advisable to consult an expert (jeweller or bespoke atelier such as Casati Milano) to perform the operation safely, especially on a valuable watch such as the 228398tbr-0004.

Is an aftermarket strap compatible with the Rolex Day-Date 40 228398tbr-0004?

Yes, provided the lug width is exactly 20mm and the construction quality is premium. Artisanal straps tailored to specification guarantee superior compatibility and durability compared to generic alternatives. On milanostraps.it you will find a specialised collection of 20mm straps tested for this model, with options in alligator, calf and other noble leathers.

How long does a leather strap last on a watch like the Day-Date 40?

A quality leather strap (alligator or vegetable-tanned calf) typically lasts 3-5 years of regular daily use, with variation due to climate, frequency of wear and maintenance. Natural leather wears progressively and develops patina—characteristics sought by enthusiasts. An artisanal strap with high construction quality tends to last toward the upper limit of this range. Casati Milano guarantees 18 months against manufacturing defects.

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