Datejust 31 Stainless Steel Domed / Jubilee / Black

About This Watch

The Rolex Datejust 31, in its 178240-0016 iteration, embodies the quiet authority of a timepiece that has defined elegance since its introduction in 1945. This reference, with its 31mm stainless steel case and domed profile, strikes a balance between classic proportions and modern wearability, while the black dial—anchored by stick indexes and hands—exudes understated sophistication. The Jubilee bracelet, a hallmark of the Datejust collection, complements the watch’s refined silhouette, its five-link design offering both comfort and a touch of ceremonial grandeur. The sapphire crystal, paired with a closed case back, ensures durability without compromising the watch’s discreet presence. At its core, the 2235 automatic movement delivers the precision and reliability for which Rolex is celebrated, featuring a Parachrom balance spring that resists magnetic interference and maintains accuracy under adverse conditions. The 100-meter water resistance, though not a feature typically flaunted, underscores the watch’s practicality without detracting from its sartorial appeal. This timepiece is for the discerning individual who values heritage and craftsmanship, seeking a watch that transcends trends yet remains perpetually relevant. It suits formal occasions with its timeless design, yet its modest dimensions and refined materials make it equally at home in everyday life—a testament to the Datejust’s enduring legacy as a symbol of quiet distinction.

In Context

At 31 mm it is small by current standards, in the range most wristwatches occupied before cases began growing through the 1990s. The case back is closed, so the movement stays out of sight, and the sapphire crystal will resist everything short of deliberate abuse. 100 m is genuine swimming resistance — more than the shape of this watch suggests it would need.

The movement winds itself from the motion of your wrist. 48 hours of reserve is enough to set it down on Friday evening and find it still running on Monday. At 28,800 vph the seconds hand advances 8 times a second.

178240-0016 is one of 24 executions of the 178240 base reference. Underneath they are the same watch; what separates this one is a black dial and a stainless steel case.

Rolex

Grey · Stainless Steel

178240-0001 · 31 mm

Rolex

Silver · Stainless Steel

178240-0005 · 31 mm

Rolex

Grey · Stainless Steel

178240-0006 · 31 mm

Rolex

Black · Stainless Steel

178240-0011 · 31 mm

Rolex

White · Stainless Steel

178240-0015 · 31 mm

Rolex

Pink · Stainless Steel

178240-0017 · 31 mm

Rolex

Black · Stainless Steel

178240-0019 · 31 mm

Rolex

Silver · Stainless Steel

178240-0022 · 31 mm

+ 15 more variants in this family.

The 2235 is the small Rolex automatic of the six-digit generation, a 20 mm movement with a date. It carried the Datejust 31 and the 26 mm Lady-Datejust from around 2000 until the 2236 replaced it. It powers 733 watches in this library. It has 31 jewels, a 48-hour reserve and a beat of 28,800 vph, and every one is a COSC chronometer. It is the same architecture as the [2236](/calibers/rolex-2236) that followed, without the silicon Syloxi hairspring and with seven hours less reserve; the [2236 piece](/blog/the-rolex-2236-the-most-common-movement-in-this-library) explains what changed. The library finds it almost entirely in the [Datejust 31](/brands/rolex/datejust-31): 682 references, the 1782xx generation, whose 45 base references and hundreds of dial variants make that collection the largest here. The 26 mm [Lady-Datejust](/brands/rolex/lady-datejust) of the 1791xx generation accounts for 29, the [Pearlmaster](/brands/rolex/pearlmaster) 29 mm and 34 mm for 19, and the 35 mm Yacht-Master for 3. A six-digit Datejust 31 reference is a 2235; the seven-digit one is a 2236, as the [reference-number guide](/blog/how-to-read-a-watch-reference-number) explains. The 2231 was its no-date sibling in the Oyster Perpetual, and the [3135](/calibers/rolex-3135) its counterpart in the 36 mm cases.

732 other watches in the library run the Rolex 2235.

Rolex

Datejust 31 Yellow Gold Diamond / Oyster / Black MOP

178158-0056 · 31 mm

Rolex

Datejust 31 Stainless Steel Diamond / Oyster / Pink MOP

178384-0061 · 31 mm

Rolex

Datejust 31 Rolesor Everose Domed / Jubilee / Black MOP

178241-0043 · 31 mm

Rolex

Datejust 31 Yellow Gold Domed / Oyster / Champagne Roman

178248-0079 · 31 mm