Rolex · Day-Date 36

Strap for Day-Date 36 Yellow Gold / Strap / Champagne Computer

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter36 mm
Reference118138-0084
FamilyDay-Date 36
MovementRolex caliber 3155 hours, minutes, seconds | date, day | chronometer
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 36 118138-0084

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 118138-0084, seen from the bench

The Rolex Day-Date 36 reference 118138-0084 is an automatic chronometer watch introduced in 1956 as the first timepiece to display day and date simultaneously. The 36 mm yellow gold Oyster case features a sapphire crystal caseback and Plexiglas dial. The caliber 3155 movement operates at 28,800 beats per second with a 48-hour power reserve. The 20 mm lug width is a fixed specification for this model and ensures compatibility with aftermarket straps. The dial displays hours, minutes, seconds, date and day of week with Arabic numerals and baton indices.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 118138-0084?

The lug width of the Rolex Day-Date 36 118138-0084 is 20 millimetres. This measurement represents the distance between the two extremities of the lateral lugs and is the determining parameter for compatibility with any aftermarket strap. Measuring the lug width requires extraction of the lateral spring bars and the use of a calliper.

What is the best material for a strap compatible with this Rolex?

Alligator represents the historically coherent choice with the aesthetics of the 1950s Day-Date 36, offering a regular grain and natural softness. Shell cordovan proposes a profound and carnal texture, whilst vegetable-tanned calf leather generates a natural patina over time. Rubber or canvas straps are inadvisable, as they betray the constructive intentionality of the yellow gold case.

How is a Rolex Day-Date 36 strap changed?

Strap replacement requires extraction of the lateral spring bars connecting the lugs to the case. Using a dedicated spring bar tool, carefully lift the internal retainers of the bars, extract them laterally, then insert the new strap. The operation must be performed with caution to avoid scratching the yellow gold case.

Is a 20mm aftermarket strap fully compatible with the 118138-0084?

Yes, any strap with a 20mm lug width is physically compatible with the 118138-0084. However, aesthetic and constructive compatibility depends on material quality, buckle choice (obligatorily in precious metal) and chromatic coherence with the yellow gold case. A steel deployante or aluminium buckle betray the intentionality of the piece.

How long does a leather strap last on a Rolex Day-Date 36?

The longevity of a leather strap depends on frequency of use, climate conditions and craftsmanship quality. Under normal conditions, a premium-quality alligator or calf leather strap resists between 3 and 5 years. Vegetable tanning ages more visibly, generating a desirable patina. Casati Milano straps include a warranty on manufacturing defects for 18 months.

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