Quick Answer
Rolex 178273 is a Datejust 31. The case measures 31 mm. It pairs a stainless steel case with an 18k yellow gold fluted bezel, a gold winding crown, and gold center links on a Jubilee bracelet. Rolex calls this mix Rolesor. The watch runs Rolex caliber 2235. Catalog listings cover the mid-2000s into the mid-2010s, when reference 278273 replaced it. A fake Rolex 178273 is a copy of that watch. Copies differ from the real item in case size, metal content, movement, and bracelet fit.
What the Number Means
Rolex code patterns tie the final digit to metal. A 3 marks steel and yellow gold. A 4 marks steel and white gold. An 8 marks solid yellow gold. The 1782 block covers the Datejust 31 case with a sapphire crystal and a quickset date. This pattern helps when a listing shows a photo and a reference number that do not match.
Specifications
- Case: 31 mm, stainless steel, polished, screw-down case back
- Bezel: 18k yellow gold, fluted
- Crystal: sapphire with a Cyclops lens, 2.5x date magnification
- Movement: caliber 2235, automatic, 28,800 vph, 48-hour power reserve, COSC certification
- Water resistance: 100 m
- Bracelet: Jubilee, steel links with gold center links, folding clasp
What Replica Versions Change
Case size comes first. Sellers list 31 mm. Calipers on many replica cases read 32 mm or 33 mm because the mid-case and bezel add width. Metal comes next. Gold on a replica is plating or PVD, not 18k. Plating depth on better examples runs 3 to 5 microns. That layer wears through at the clasp and crown with daily use.
Movement is the third difference. Copies use the ETA 2824-2, the Sellita SW200, the Sea-Gull ST2130, or low-cost 2813 movements. The 2824-2 and the SW200 beat at 28,800 vph, the same rate as caliber 2235. The 2813 beats at 21,600 vph. A timegrapher shows rate in seconds per day and amplitude. Genuine caliber 2235 holds about 48 hours of reserve. The 2824-2 holds about 38 hours.
Bracelet fit is the fourth. Hollow end links rattle against the case. Solid end links sit tight. Count the links on a Jubilee. Many Datejust 31 builds use 22 links and a hidden clasp. Check the clasp stamp and the coronet.
Checks Before You Buy
- Measure the case across the bezel. Target 31 mm.
- Weigh the watch. Gold center links and a gold bezel add mass. Plated steel reads light.
- Watch the second hand. 8 ticks per second points to a 28,800 vph movement. 6 ticks per second points to 21,600 vph.
- Look at the date. Cyclops magnification on genuine Rolex sapphire is 2.5x. A weak lens shows a small date.
- Read the dial text. Letter spacing and coronet shape vary on copies.
Limits
No replica carries a Rolex warranty card, a COSC certificate, or a 100 m water rating. Pressure testing is not part of replica assembly. Replica 178273 prices run from about $80 to $500. Genuine examples sell for far more on the secondary market, and dial type, box, and papers move that number.