The Rolex reference 178273 is a Datejust 31 in Rolesor: a 31 mm Oystersteel case paired with a solid 18k yellow-gold fluted bezel and a two-tone Jubilee bracelet. Inside sits the automatic Calibre 2236 with a 55-hour power reserve. Production ran from roughly 2009 through the late 2010s, when the line was updated. That number is a precise factory code, not a style. A watch advertised as a "replica 178273" is a different object entirely, and in the United States trafficking in counterfeit watches is a federal crime under 18 U.S.C. § 2320.
Before you start
- Know the exact reference you are looking at. 178273 means steel case, yellow-gold fluted bezel. 178274 is white gold. 178240 is steel with a domed bezel.
- Have a 10x loupe and a phone camera with macro mode.
- Buy only from a seller who will provide movement photos, an in-hand video, and a written return window.
What the number breaks down to
- 178 — Datejust 31 family, introduced as the mid-size Datejust.
- 273 — Rolesor build: Oystersteel case, 18k yellow-gold fluted bezel.
- Case size — 31 mm diameter, 10.6 mm thick, 100 m water resistance.
- Movement — Calibre 2236, 28,800 vph, Syloxi silicon hairspring, 55-hour reserve.
How to check a 178273 step by step
- Measure the case with calipers. It should read 31 mm across at the bezel, not 33 or 28.
- Inspect the bezel under the loupe. Genuine flutes are cut into solid gold, with crisp mirrored edges and no plating lines at the case junction.
- Read the dial text. Print is raised and flat, spacing is even, and the date window sits centered under the Rolex coronet.
- Check the date wheel. Numbers are correct for the font and snap over at midnight, not drift in over 30 minutes.
- Look at the inner bezel ring, or rehaut. The reference and serial engravings are shallow, sharp, and sit inside the crystal at 6 and 12.
- Examine the bracelet and clasp. Gold runs through the clasp crown, links are tight and drilled cleanly, and the Oysterclasp engages with a firm click.
- Weigh the watch. A complete 178273 on a Jubilee sits in a narrow weight band; a plated copy is usually several grams light.
- Have a watchmaker pull the movement data. Amplitude, beat rate, and the 2236's silicon hairspring cannot be faked on a timing machine report.
What replicas get wrong
No copy uses a Rolex Calibre 2236. Instead you get a generic automatic movement wrapped in plating, which means the gold color wears through at the crown and lugs, the fluted bezel softens within a year, and the case will not hold water resistance. There is no factory parts channel, so service becomes a repair shop hunt. Resale is effectively zero, while a genuine 178273 holds value in the seven to eleven thousand dollar range on the secondary market, depending on dial, bracelet stretch, and papers. U.S. Customs and Border Protection routinely seizes counterfeit watch shipments at ports of entry, which means your money is gone if the package is intercepted.
Bottom line
Learn the 178273 reference first, verify the movement second, and buy the seller as much as the watch. If a listing leans on the word "replica," treat it as a warning label rather than a bargain.