Rolex · Datejust 31

Strap for Datejust 31 Yellow Gold Fluted / President / Silver Diamond

Takes 16 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width16 mm
Case diameter31 mm
Reference178278-0040
FamilyDatejust 31
MovementRolex caliber 2235 hours, minutes, seconds | date | chronometer
CaseYellow Gold

Spring bar

Spring bars for Rolex

The right category for this model · choose the 16 mm size

Straps for the Datejust 31 178278-0040

Selected for the 16 mm lug width

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The Datejust 31 178278-0040, seen from the bench

The Datejust 31 represents the feminine version of the Rolex Datejust collection, with a 31mm case diameter. It features the automatic caliber 2235 certified as a chronometer, with indications of hours, minutes, seconds and date. The 16mm lugs complete the technical specifications of the model.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 ref. 178278-0040?

The lug width of the Rolex Datejust 31 178278-0040 is 16mm. This measurement is specific to all Datejust 31 models and is essential when selecting compatible straps. You can verify this dimension by placing a calliper between the lugs at their widest point.

Which strap material is best suited for a yellow gold Rolex Datejust 31?

For a yellow gold 18-carat Datejust 31, the most refined materials are alligator with vegetable tanning, shell cordovan, and calf leather. Alligator with natural grain texture harmonises exceptionally well with gold patina, developing character over time. Shell cordovan provides unmatched natural lustre and durability. Calf leather is a contemporary choice offering superior resistance and deep colour absorption.

How do I change the strap on a Rolex Datejust 31?

Strap replacement requires a spring bar tool to remove the elastic pins (spring bars) securing the strap to the lugs. Position the watch face-down on a soft cloth, insert the tool into the space between case and strap, release the spring bar pin, and remove the strap. Repeat on the opposite lug. For models with a metal oyster link bracelet, the process may be more complex and professional adjustment is recommended.

Is an aftermarket strap truly compatible with the Datejust 31 178278-0040?

Yes, provided the lug width is precisely 16mm. Compatibility is guaranteed by exact lug width measurement with a tolerance of ±0.2mm. High-quality artisanal straps from specialised manufacturers (such as Casati Milano) ensure complete compatibility whilst maintaining superior construction standards compared to generic components. Always verify specifications with the seller.

What is the expected lifespan of a leather strap on a Rolex Datejust 31?

Longevity varies according to material and frequency of use. A high-quality alligator strap (vegetable-tanned) typically lasts 2–4 years in daily wear, with potential for aesthetic restoration. Shell cordovan, being more durable, can last 4–6 years whilst maintaining structural performance. Calf leather has intermediate longevity (2–3 years in daily use). Climate, humidity, and cleaning frequency significantly influence durability.

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