Rolex · Datejust 31

Strap for Datejust 31 Stainless Steel / Yellow Gold / Diamond / Silver - Diamond / 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
Reference278383rbr-0020
FamilyDatejust 31
MovementRolex caliber 2236 Hours, Minutes, Seconds | Date | Chronometer
CaseYellow Gold, Stainless Steel

Spring bar

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

Straps for the Datejust 31 278383rbr-0020

Selected for the 16 mm lug width

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The Datejust 31 278383rbr-0020, seen from the bench

The Rolex Datejust 31 ref. 278383RBR-0020 is a classic timepiece from the lineage established in 1945. It combines a 31mm Oystersteel case with 18-carat yellow gold fluted bezel and diamond-set dial, paired with a diamond-set bezel. The Rolex caliber 2236 manufacture movement features a silicon Syloxi hairspring, 55-hour power reserve, 28,800 vph frequency, and Superlative Chronometer certification (±2 sec/day). The case offers 100-meter water resistance via Twinlock crown. The lug width is 16mm, requiring specifically designed straps to maintain proportional compatibility and architectural integrity of the case.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 278383rbr-0020?

The Rolex Datejust 31 ref. 278383rbr-0020 has a lug width of 16mm. This is a non-standard size compared to larger Datejust references. It is essential to verify this measurement with a calliper before purchasing an aftermarket strap, by measuring the internal distance between the two lower lugs of the case.

What is the best strap for the Rolex Datejust 31 278383rbr-0020?

For this yellow gold and stainless steel reference with a diamond-set bezel, the most appropriate straps are in Mississippiensis alligator (hornback or square scale grain) or vegetable-tanned calf leather. Both materials complement the reflection of the diamonds without overpowering the dial. Shell cordovan is an alternative for those seeking a dense, progressively character-developing surface.

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

Strap replacement requires a fine-tipped springbar tool to remove the spring bars from the lugs. On a 16mm Datejust 31, it is advisable to use precision instruments to avoid scratching the yellow gold and stainless steel case. If in doubt, Casati Milano offers a professional fitting service at the atelier by appointment.

Are there aftermarket straps compatible with the Rolex Datejust 31 278383rbr-0020?

Yes. Aftermarket straps with a 16mm lug width are compatible with this reference, provided that the end-piece curvature matches the profile of the Oyster case. Milano Straps offers a selection of handcrafted 16mm straps in various materials and colours, manufactured to the precise dimensions required for this case diameter.

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

Longevity depends on the material and daily use. A quality alligator strap with vegetable tanning can last between 2 and 5 years with proper care — avoiding prolonged exposure to moisture and perspiration. Shell cordovan tends to last longer due to the compactness of its fibres. All Milano Straps straps carry an 18-month warranty against manufacturing defects.

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