Ultra Thin Watch-Patek Philippe 5370 Split Seconds Chronograph

Front of Patek Philippe 5370 Split Seconds Chronograph

Patek Philippe ref. 5370 split seconds watch is an ultra thin movement which presentd at last SIHH. The only two buttons may be seen as additional complications.The split seconds complication as the stand alone feature also makes it a purist watch.  Front of Patek Philippe 5370 Split Seconds Chronograph 02

The movement in the ref.5959 is the Patek proprietary movement base: the CHR 27-525 PS. CHronographe à Rattrapante being the prefix making reference to the split seconds function. The ref. 5959 was also the first in-house chronograph made by Patek Philippe. Earlier chronographs, including the illustrious ref. 3970 and the ref. 5004  are based on a heavily modified Lemania 2310 ébauche.

The Patek Philippe 5370 Split Seconds Chronograph has an imposing presence. Measuring some 41mm in diameter, it sits comfortably on the wrist, but is larger than most Patek Philippe watches. The case design is sensuous, featuring beautiful curved lines which hug the round case and the elegant sloped shoulders of the bezel. It is available only in platinum, though it may be offered in other gold metals in the future.Front of Patek Philippe 5370 Split Seconds Chronograph

The dial is grand feu black enamel, and is rather resplendent in its deep black, shiny finish. The markers are in white print offer a high contrast and good legibility. Hour numerals are in Breguet style, and in white gold appliqué. Elegant leaf shaped hands, filled with superluminova gives the watch a rather upperclass feel, in line with its heritage as the Grande Maison.

The black enamel dial deserves special mention. Black enamel is perhaps the most difficult to manufacture, as the deep black glossy surface shows up any defects and artifacts common in many enamel dials easily. Interestingly, this is the second black enamel dial to appear in 2015. In SIHH, Lange introduced its Lange 1 Tourbillon Handswerkskunst which also feature a flawless black grand feu enamel dial. The only other notable black enamel dial was made by Jacquet Droz in its early years, featured on their Grande Seconds model with a particularly thick enamel layer.Side of Patek Philippe 5370 Split Seconds Chronograph 02

The ref. 5370 dial is made by Cadrans Stern Frères, a company owned by the Sterns who currently own Patek Philippe. They bought the firm in 1932 and have held it privately in the family since. The dial is solid white gold, and is first coated by black enamel by hand. Enamel is vitreous in nature, being based on glass, melts when fired at the oven at 850°C. It is allowed to solidify and several layers are fired. The dial is then drilled by hand to make the openings, and this must be done with great care and skill, as the enamel is very hard, but brittle. The drilling can break the dial easily, destroying the entire dial. These piercings are used to mount the feet of the appliqué numerals, and also for the hands’ pinions to pass through.

The design is beautiful, with the layout showcasing Patek Philippe’s craft. Note the magnificently curved levers and springs. Note also that each lever and spring is carefully polished and anglaged. As is expected, all screws are polished and sit in polished, chamfered openings. The steel chronograph works are straight grained on their top surfaces and also anglaged.The main column wheel commanding the functions of the chronograph is topped with a black polished steel cap. Enormous attention to detail is paid to this cap. The edges are beautifully anglaged, and the center part, holding the screw pin for the column wheel features chamfered sides which are also polished.