A fake Audemars Piguet Royal Oak 5402ST is a copy of the 39 mm steel "Jumbo" that Audemars Piguet launched in 1972. Genuine 5402ST watches trade in six figures at auction. Copies exist, but most replica Royal Oaks sold today copy newer references, such as the 15202ST and the 15500ST. Few replicas match the 5402ST case, dial, and movement.

Reference facts

  • Shown in 1972. Design by Gerald Genta.
  • Steel case, 39 mm wide, about 8 mm thick.
  • Octagonal bezel with eight screws. On steel 5402ST watches the screws are white gold.
  • Integrated steel bracelet. Wide at the case, narrow at the clasp.
  • Caliber 2121, automatic, derived from the Jaeger-LeCoultre 920.
  • Production ran to 1977. Series letters A, B, C, D.

Dial checks

The dial uses a petite tapisserie pattern, a grid of small raised squares cut into the surface. The squares sit in tight rows. A-series dials carry the AP monogram at 12 o'clock. Later B and C series print the name Audemars Piguet in full. The date window sits at 3 o'clock with thin numerals. Fake dials show a wider grid, flat squares, thick print, and date fonts with the wrong numeral shapes.

Movement checks

Caliber 2121: automatic, 36 jewels, 19,800 vibrations per hour, central rotor, date at 3 o'clock. Replicas of the Royal Oak use ETA 2892, Miyota, Seiko, or Chinese automatic movements, or decorated movements with a false rotor. Ask for a photo of the movement with the case back removed. Look for the caliber number and the maker's name. Many sellers do not supply this photo.

Case back and bracelet

The case back is solid steel. Reference and serial numbers are stamped. Engraving depth, font, and position change between series. Replica case backs use wrong fonts and place the reference number in the wrong spot. Bracelet links are machined, not folded. Link counts and taper differ from modern replicas. Check the clasp marking against photos of the same series.

Common faults on copies

  1. Case thickness above 9 mm.
  2. Bezel screws with cross heads or wrong slot widths.
  3. Dial grid squares that are too large.
  4. Printed text with wrong weight and spacing.
  5. Hands that are too wide or too long.
  6. Modern movements with no 2121 markings.
  7. Case back stamps in the wrong position.

Prices and part-built watches

Steel 5402ST examples sell in six figures at auction when they are complete and original. A-series watches with the monogram at 12 o'clock bring the highest prices. Some watches on the market are assembled from genuine and aftermarket parts. Serial and reference records from Audemars Piguet can confirm a case. No public list of every 5402ST serial exists. Treat any 5402ST offered far below market as suspect.