Rolex 278240-0018 Datejust 31mm Stainless Steel Jubilee Blue – Roman Dial Watch

Rolex Datejust 31 – Ref. 278240-0018

The Rolex Datejust 31 Ref. 278240-0018 is a sophisticated women’s timepiece that blends classic Rolex design with modern refinements. Crafted entirely in Oystersteel, it features a bright blue sunray-finish dial, a domed bezel, and the reliable, high-performance Calibre 2236 movement. The 31 mm case size makes it elegantly wearable for small-to-medium wrists, while the performance specs and finishing retain the hallmark robustness Rolex is known for.

Case & Exterior Design

This model uses Rolex’s Oystersteel, a 904L-grade stainless steel alloy known for its corrosion resistance and exceptional finish. The case diameter is 31 mm, with a domed bezel that adds a subtle classic touch. The construction includes a screw-down Twinlock crown and a caseback tightly sealed to provide water resistance up to 100 meters (330 feet).

Bright “Sunray” Blue Dial

The dial is finished in a radiant blue sunray pattern that creates a subtle play of light across its surface as the wrist moves. The sunray effect is produced via fine brushing from the dial’s center outward, giving dynamic reflections. The dial is minimal but legible, with baton hour markers and dauphine-style hands, and the signature Rolex Cyclops lens over the date aperture at 3 o’clock, magnifying the date for easy reading.

Movement – Calibre 2236

Inside beats the in-house Rolex Calibre 2236, a self-winding mechanical movement. This caliber is enhanced with the Syloxi silicon hairspring and Paraflex shock absorbers, improving precision and robustness. After casing, the watch is certified as a Superlative Chronometer, guaranteeing a precision of −2/+2 seconds per day. It also offers about 55 hours of power reserve, giving practical autonomy to the wearer.

Bracelet & Comfort

The 278240-0018 is paired with a five-piece Jubilee bracelet, known for its elegance, flexibility, and comfort. The clasp is a folding Oysterclasp, discreet and secure. The Jubilee bracelet compliments the overall refined aesthetic of the watch while ensuring it sits fluidly around the wrist.

Key Specifications

• Reference: 278240-0018
• Case Material: Oystersteel
• Case Size: 31 mm
• Bezel: Domed steel bezel
• Dial: Bright blue sunray finish
• Movement: Calibre 2236, automatic
• Power Reserve: ~55 hours
• Water Resistance: 100 meters / 330 feet
• Bracelet: Jubilee, five-piece links
• Certification: Rolex Superlative Chronometer

What Sets 278240-0018 Apart

• Compact yet capable: The 31 mm case balances elegance and wearability, making it ideal for smaller wrists without compromising on presence.
• Distinctive blue sunray dial: The radiant blue finish adds personality and depth, distinguishing it from more conventional dials.
• Rolex reliability: Equipped with Calibre 2236 and Syloxi technology, it delivers precision, shock resistance, and solid power reserve.
• Jubilee bracelet comfort: The flexible links and refined look enhance daily wear and style.

Conclusion

The Rolex Datejust 31 Ref. 278240-0018 is a timeless expression of elegance and technical excellence. With its bright blue sunray dial, Oystersteel build, and reliable movement, it offers luxury with practicality. Perfect for those who want a refined Rolex in a smaller, versatile size—ideal for daily wear or more formal occasions.