Rolex · Datejust 31

Strap for Datejust 31 Stainless Steel / Jubilee / White - 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
Reference278240-0004
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 278240-0004

Selected for the 16 mm lug width

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The Datejust 31 278240-0004, seen from the bench

The Datejust 31 is equipped with the automatic chronometer-certified Caliber 2236, with hour, minute, second and date indications. The case has a diameter of 31mm with 16mm lugs. The movement offers the basic functions of a timepiece with a date complication.

Frequently asked questions

What is the lug width of the Rolex Datejust 31 278240-0004?

The lug width of the Rolex Datejust 31 278240-0004 is 16 millimetres. This measurement represents the internal distance between the two metal terminals of the case and is essential for purchasing a compatible strap. When measuring with a digital calliper, ensure zero tolerance to guarantee secure attachment and water resistance.

Which strap material is recommended for the Datejust 31 278240-0004?

Alligator is the traditional choice for pure elegance, with natural and regular grain. Vegetable-tanned calf develops patina over time. Shell cordovan offers superior strength and compactness. Rubber straps guarantee daily practicality without compromise. Choice depends on use: formal wear for alligator, daily versatility for calf, sporty for rubber.

How do you change the strap on a Rolex Datejust 31 278240-0004?

Strap replacement requires a specific tool to extract the spring bar from the terminals of the case. Position the watch on a soft surface, locate the small opening on the terminal, insert the tool to compress the spring and retract the bar. Repeat on the other side. Mount the new strap by reversing the procedure, ensuring the bar clicks securely into position. If inexperienced, consult an authorised Rolex centre or qualified watchmaker.

Does using an aftermarket compatible strap void the Rolex 278240-0004 warranty?

Rolex does not invalidate international warranty coverage for strap changes with certified aftermarket products. However, if anomalies result from incorrect installation, Rolex may exclude coverage for that specific defect. We recommend documenting the installation and using straps from verified artisans, such as Casati Milano, which guarantee compatibility and quality.

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

A quality leather strap with vegetable tanning typically lasts 18–24 months with daily use and routine maintenance. Longevity depends on humidity exposure, climate and frequency of wear. Dense leathers such as shell cordovan exceed three years. A rubber strap maintains structural integrity for 3–4 years. To extend lifespan, avoid prolonged water exposure and occasionally apply conditioning treatments to natural leathers.

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