Rolex · Datejust 31

Strap for Datejust 31 Stainless Steel Diamond / Oyster / Pink

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-0017
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-0017

Selected for the 16 mm lug width

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The Datejust 31 278384rbr-0017, seen from the bench

The Datejust 31 reference 278384rbr-0017 is equipped with the automatic caliber 2236 with hour, minute, second and date functions, certified chronometer. The case has a diameter of 31mm with 16mm lugs. The movement offers date indication in addition to the standard hour functions.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 ref. 278384rbr-0017?

The lug width of the Rolex Datejust 31 ref. 278384rbr-0017 is 16mm. This measurement is calculated as the optimal proportion between the 31mm case diameter and the wrist, measured at the internal exit points of the spring bars from the case at 12 and 6 o'clock positions. A compatible strap must respect this dimension precisely to avoid visual misalignment and structural stress on the metal tabs.

Which type of strap is recommended for the Datejust 31 278384rbr-0017?

Alligator leather represents absolute excellence for this model, thanks to its natural texture and elasticity that dialogue perfectly with the two-tone case in white gold and steel. Vegetable-tanned calf leather is a sophisticated and versatile alternative, whilst shell cordovan offers a refined solution for those who appreciate conscious ageing of leather. For more dynamic use, FKM rubber maintains balanced proportions.

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

Strap replacement is accomplished by extracting the spring bars from the case lugs. A spring bar tool is used to compress the small internal springs and slide them out from the case. It is a delicate operation requiring patience and attention: excessive pressure risks scratching the case. If unfamiliar with the procedure, it is advisable to consult a professional or specialised atelier such as Casati Milano.

Is an aftermarket strap compatible with the Rolex Datejust 31 ref. 278384rbr-0017?

Yes, provided the strap is designed for a 16mm lug width. Many artisanal aftermarket straps surpass OEM Rolex products in material quality: carefully selected leather, conscious tanning processes and hand-crafted construction ensure longevity and unique patina development. Before purchase, always verify that the supplier explicitly specifies 16mm as the lug width.

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

Durability depends on leather quality, frequency of use and environmental conditions. Alligator or vegetable-tanned calf leather, with ordinary maintenance (drying after moisture exposure, protection from prolonged UV radiation), maintain structural integrity for 4 to 7 years of daily wear. FKM rubber resists longer (8 to 10 years), though it gradually loses elasticity. A strap does not age: it evolves. Patina is beauty, not defect.

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