Rolex · Datejust 31

Strap for Datejust 31 Stainless Steel / Diamond / Blue - Floral / Jubilee

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
Reference278384RBR-0040
FamilyDatejust 31
MovementRolex caliber 2236 Hours, Minutes, Seconds | Date | Chronometer
CaseWhite Gold, Stainless Steel

Spring bar

Spring bars for Rolex

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

Straps for the Datejust 31 278384RBR-0040

Selected for the 16 mm lug width

All 16 mm straps →

The Datejust 31 278384RBR-0040, seen from the bench

The Rolex Datejust 31 reference 278384RBR-0040 features a 31mm white gold and Oystersteel case (white Rolesor) with a fluted diamond-set bezel and diamond-set dial. It houses the Rolex Caliber 2236 movement, COSC-certified and meeting Superlative Chronometer standards with ±2 seconds/day accuracy. Functions include hours, minutes, central seconds, and date window at 3 o'clock with rapid correction. The lug width is 16mm, a size that requires specialized aftermarket strap manufacturers for proper fitment. Approximately 55 hours power reserve.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 278384RBR-0040?

The lug width of the Rolex Datejust 31 ref. 278384RBR-0040 is 16mm. This measurement is taken between the two upper lugs of the case, at the point of contact with the strap, and is the essential parameter for selecting a compatible aftermarket strap.

What is the best strap for the Rolex Datejust 31 278384RBR-0040?

For a white Rolesor case with a diamond-set bezel, a glossy or semi-glossy alligator strap is the most aesthetically coherent choice, as the rectangular grain complements the fluted texture of the bezel. Shell cordovan or vegetable-tanned calf leather are excellent alternatives, offering versatility and a noble patina that develops gracefully over time.

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

The strap on a Rolex Datejust 31 is removed using a spring bar tool to extract the spring bars connecting the strap to the case lugs. It is advisable to work on a watchmaker's cushion to avoid scratching the white gold surfaces, and to entrust the operation to a qualified watchmaker or experienced strap craftsman.

Are there aftermarket straps compatible with the Rolex Datejust 31 278384RBR-0040?

Yes, high-quality aftermarket straps are available for the Datejust 31, provided they feature a 16mm attachment width. Milano Straps and the Casati Milano atelier produce bespoke straps in alligator, calf leather and shell cordovan, precisely dimensioned for 16mm lugs and customisable in length and finish to suit individual wrist circumferences.

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

The lifespan of a leather strap depends on the quality of the hide, daily care and frequency of use. A high-quality alligator or shell cordovan strap, kept away from water and moisture and rotated with other straps, can last between three and six years while developing a distinguished patina. Vegetable-tanned leather straps of the finest quality acquire a characteristic patina over time that enhances their aesthetic value.

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.

Request an appointment →

Casati Milano · Via XX Settembre 15, Milan · by appointment only