P1 Factory Patek Philippe Nautilus 5980/60G-001 – Custom CH28-520 Movement QC Review

P1 Factory Patek Philippe Nautilus 5980/60G-001 – Custom CH28-520 Movement QC Review

The P1 Factory Patek Philippe Nautilus 5980/60G-001 features a white-gold-plated case, blue-gray dial, calfskin leather strap and sapphire crystal.

Our inspection found the overall appearance and workmanship of this sample satisfactory. This QC review focuses on the custom CH28-520 movement, chronograph functionality and the screw-secured clasp mechanism.

1. Actual QC Test Results

QC Item Measured Result
Factory P1 Factory
Reference 5980/60G-001
Case White-Gold Plated
Dial Blue-Gray
Strap Calfskin Leather
Crystal Sapphire
Movement Custom CH28-520
Daily Rate -4 s/day
Amplitude 266°
Beat Error 0.4ms
Beat Rate 28,800 BPH
Measured Width 43mm
Measured Thickness 14.7mm
Measured Weight 126.9g

These results apply to the individual QC sample. Minor variations may occur between watches and under different testing conditions.

2. Custom CH28-520 Movement and Timekeeping Performance

This version uses a custom CH28-520 movement.

The timegrapher results fall within our usual pre-shipment daily-rate reference range of ±0–15 seconds per day. The amplitude and beat error readings provide additional information about the movement’s condition during testing.

A single timegrapher measurement does not guarantee long-term accuracy. Actual performance may vary depending on power reserve and wearing position.

3. Chronograph Function Test

Our QC inspection included physical testing of the chronograph mechanism, confirming that:

* Chronograph minute counter: Operational.
* Chronograph hour counter: Operational.

Both functions provide actual elapsed-time measurement rather than decorative indications.

For the Nautilus 5980 series, verifying these functions is an important part of evaluating different movement configurations.

4. White-Gold-Plated Case and Clasp Construction

The watch features a white-gold-plated case, which is different from a solid white-gold case.

The plating is a surface finish. To help preserve its appearance, avoid abrasive contact, strong impacts and chemical cleaning products that may affect the plated surface.

Important Clasp Adjustment Notice

Screw-secured clasp adjustment pin

Our inspection found that the clasp adjustment pin uses a threaded screw mechanism rather than a conventional friction-fit pin.

After adjusting the strap length, the retaining screw must be securely tightened and the clasp connection checked before wearing the watch.

If the screw is not properly secured, it may loosen during wear and increase the risk of the watch becoming detached.

Avoid overtightening, as excessive force may damage the threads. If unfamiliar with this type of fastening mechanism, have the adjustment performed by an experienced watch technician.

5. Overall QC Assessment

The P1 Factory Nautilus 5980/60G-001 demonstrated satisfactory overall workmanship, timekeeping performance within our QC reference range and operational chronograph functions.

Beyond the movement and exterior finishing, correct clasp adjustment is an important consideration for everyday use.

These findings provide a practical technical reference for comparing different Nautilus 5980 versions.

FAQ

1. What movement does this watch use?

It uses a custom CH28-520 movement operating at 28,800 BPH. This designation does not imply that its internal construction is identical to the original Patek Philippe caliber.

2. Is a white-gold-plated case the same as solid white gold?

No. White-gold plating is a surface treatment and should not be confused with a solid white-gold case.

3. What should I check after adjusting the strap length?

The clasp uses a screw-secured adjustment pin. After making adjustments, tighten the retaining screw and confirm that the clasp connection is secure.