A replica AP Royal Oak 15400 with a screw-down crown uses threaded surfaces on the crown and the case tube so the crown tightens into the case instead of pulling straight out. That threaded joint presses a gasket against the tube and closes off the winding stem opening. The genuine Royal Oak 15400ST carries a water resistance rating of only 50 m, so the screw-down crown is a splash and dust barrier, not a diving feature.
Why the screw-down crown matters on the 15400
The 15400 is a 41 mm watch with an integrated bracelet and a slim case, and its crown sits close to the case flank with almost no overhang. That tight geometry makes the crown the easiest place for a replica to look wrong. A correctly machined screw-down crown sits flush, lines up with the AP logo, and turns without binding.
AP Royal Oak 15400 Replica Discussion: What to Check Before Buying
How does a screw-down crown differ from a push-pull crown?
A push-pull crown relies on friction and a single gasket near the stem, and it pulls straight out to the setting positions. A screw-down crown adds threads and a second gasket, so you must unscrew it before the crown will pop out for time setting. On a replica, a push-pull crown dressed up to look threaded is one of the most common shortcuts.
AP Royal Oak 15400 Replica vs Genuine: Key Differences
How to check the screw-down crown on a replica 15400
- Unscrew counterclockwise. The crown should release after roughly one to two full turns and then spring outward on its own.
- Feel the threads. They should engage smoothly for the whole travel. Gritty, grinding, or cross-threaded movement points to soft metal or a poorly cut tube.
- Check the seated position. When tightened, the crown should sit flush or slightly proud of the case with an even gap all around.
- Inspect the logo. The AP monogram should be centered and upright when the crown is fully closed.
- Test stem play. With the crown pulled to the setting position, the stem should feel firm and should not wobble side to side.
Does a screw-down crown make a replica 15400 waterproof?
No. A screw-down crown is one seal among several, and it only works when the caseback gasket, crystal gasket, and crown gasket are all intact and correctly seated. Most replicas leave the factory without pressure testing, and gaskets sit dry until the first service. Treat any replica 15400 as splash resistant at best, and keep it out of pools, showers, and salt water.
Which specs should match the genuine 15400?
- Case size: 41 mm diameter with a thin bezel and octagonal bezel screws aligned to the case.
- Crown position: at 3 o'clock, sized to sit within the case flank without overhang.
- Winding feel: smooth, slightly firm resistance, not loose or springy.
- Water resistance rating: 50 m on the genuine reference, so a replica claiming 100 m or more is overselling.
FAQ
Should the crown sit flush when screwed down?
Yes. A properly threaded crown closes until it meets the case tube and stops with no visible gap. A gap usually means the tube is too short or the gasket is missing.
How many turns should it take to unscrew?
Typically between one and two turns. If the crown needs many turns or releases immediately, the threading is either shallow or stripped.
Can a watchmaker add a working screw-down crown to a replica?
A watchmaker can sometimes re-tap the case tube, but the result depends on case metal quality and rarely matches factory tolerances. The cost often exceeds the value of the watch.
Authenticity and legal note
A replica is not a genuine Audemars Piguet, and it contains no genuine movement, case, or warranty support. Importing or selling counterfeit goods is illegal in the United States and many other countries, and shipments can be seized. Buy only what you can legally own where you live.