Rolex · Datejust 31

Strap for Datejust 31 Stainless Steel / Oyster / Pink - Roman

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
Reference278240-0013
FamilyDatejust 31
MovementRolex caliber 2236 hours, minutes, seconds | date | chronometer
Year2020
CaseStainless Steel

Spring bar

Spring bars for Rolex

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

Straps for the Datejust 31 278240-0013

Selected for the 16 mm lug width

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The Datejust 31 278240-0013, seen from the bench

The Rolex Datejust 31 ref. 278240-0013 is a 31mm stainless steel watch that defines elegant wristwatch standards since 1945. It features a date window at 3 o'clock under a sapphire cyclops, stick indices, and Dauphine hands. The case houses the Rolex caliber 2236 automatic movement with Syloxi silicon balance wheel and hairspring, certified COSC chronometer with -2/+2 second precision and 55-hour power reserve. Oystersteel construction with Twinlock crown ensures 100-meter water resistance. The lug width is 16mm.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 278240-0013?

The Rolex Datejust 31 ref. 278240-0013 has a lug width of 16mm. This measurement should be taken internally between the two lugs using a digital calliper, pressed against the case, to ensure accurate compatibility with aftermarket straps.

What is the best strap for the Rolex Datejust 31 278240-0013?

For the Datejust 31 in Oystersteel, a vegetable-tanned alligator strap is the most refined choice for formal and semi-formal wear, as the grain develops a distinctive patina over time. Box calf leather is preferable for daily use, whilst a nylon NATO or FKM rubber strap suits sporting and aquatic environments.

How do you change the strap on a Rolex Datejust 31 278240-0013?

To replace the strap, the spring bars must be removed from the lugs using a double-ended springbar tool. Insert the forked tip between the lug and the strap end piece, then compress the spring bar until it releases. The process takes approximately two minutes per side and does not require specialist watchmaking tools. It is advisable to work on a soft mat to protect the case finish.

Are there aftermarket straps compatible with the Rolex Datejust 31 278240-0013?

Yes. Any strap with a 16mm attachment and standard spring bars is compatible with the Datejust 31 278240-0013. Milano Straps offers a curated range of handcrafted straps in 16mm width, including options in alligator, calf leather, NATO, and rubber. A fully bespoke service is also available through Casati Milano.

How long does a leather strap last on a Rolex Datejust 31?

The lifespan of a leather strap depends on the material, frequency of wear, and exposure conditions. A quality vegetable-tanned alligator strap, used with care and rotated with other straps, can last between three and seven years. Contact with water, perspiration, and cosmetics accelerates deterioration; it is recommended to remove leather straps before aquatic or sporting activities.

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