To qualify for the Patek Philippe Seal, a movement must fulfill many strict requirements with respect to its technical assets and its finishing. Compliance with this criterion results in masterpieces that are admired by knowledgeable connoisseurs for their outstanding functionality, long-term reliability, superior rate accuracy and peerless beauty.
The flanks of steel parts must be satin-finished, their angles and sinks polished. The visible surfaces must be smoothed except for the regulator assembly, which must be polished. Screw heads must be polished or circular grained, their circumferences and slots chamfered.
The bearing jewels in every movement must have polished holes, especially in going trains as well as in specific self-winding wheel trains and escapements. The jewels on the bridge side must be rounded and have polished sinks except in cases where this would jeopardize their secure fit. In addition to bearing jewels, all systems that improve the rotation of pivots are permissible.
All exterior surfaces of the spring barrel and barrel cover as well as the ratchet, the crown wheel and all round components must be meticulously finished.
The tooth flanks of steel wheels are to be polished with wooden wheels.
The upper sides of all bridges must be decorated and provided with polished chamfers and sinks. The undersides and flanks of the bridges must be meticulously finished. The contact surfaces are precision-machined and have angled edges.
The surfaces of the main and any secondary plates are decorated with circular graining. The full-height plate cut-outs are chamfered, the sinks polished.
The balance spring must be mechanically attached in a manner that is perfectly true in the flat and in the round. The attachment must guarantee that the spring withstands shocks pursuant to the NIHS standard.
Rate accuracy adjustments must act on the inertia of the balance wheel assembly. Regulators with index pointers or slots are also permitted if they incorporate a steadying device, except in ultra-thin calibers where such regulators are not required. In conventional balance wheels, the rim must be chamfered and diamond-polished. The spokes must be sandblasted or circular grained on the top side. The spokes and the rim must be meticulously finished on the bottom side.
The winding rotors must be made of a precious metal and shall be decorated.