The case of the new Ref. 5971 is a masterpiece in itself and a showcase of the jeweler’s art. Crafted completely from 950 platinum, it challenges casemakers considerably more than a gold or steel counterpart. In keeping with its cool hue, platinum is not easy to work: it resists punching, milling, drilling and polishing. It takes twice as long to machine and punishes tools much more than gold. The reward is a case of impressive weight and inimitable color. The Ref. 5971 is endowed not only with a small diamond between the lugs at 6 o’clock (like all current Patek Philippe models with platinum cases); it also has a broadened bezel studded with 36 baguette diamonds totaling approximately four carats, each flawless rare white Top Wesselton. The diamonds are perfectly set by the manufacture’s in-house jewelers, who rank among the most respected experts of their craft.



The heart that beats inside the Ref. 5971 is a gem in its own right. It is the mechanical caliber CH 27-70 Q movement, agreed by most connoisseurs to be the most beautiful classic column- wheel chronograph mechanism in existence. The ébauche is manufactured by Nouvelle Lémania exclusively for Patek Philippe, further refined at the Geneva workshops, and vested with a perpetual calendar that automatically takes into account the different number of days in each month, including leap years. The movement has a Gyromax balance, and the column wheel features a polished cap. The edges of the steel parts are carefully chamfered and burnished and the leaves of the pinions individually polished to reduce friction in the wheel train. The result is a movement that fascinates the observer with its peerless aesthetics and perfect finish as well as the fascinating contrasts of mirrored bevels, frosted surfaces, artistic decorations, and the mesmerizing interplay of 353 individual parts. It ticks at a rate of 18,000 semi-oscillations per hour (2.5 Hz) and with the chronograph function is capable of measuring times with an accuracy of one-fifth of a second. The watch comes with two case backs: a solid-platinum back and a sapphire-crystal back.

Spectrum of time

The black dial shows a broad spectrum of time indications. The hours and minutes are indicated with two white-gold leaf-shaped hands and the chronograph seconds with a slender center sweep hand. The date and month of the perpetual calendar appear in two small apertures at 12 o’clock. Subsidiary dials are provided for the running seconds and the 24-hour indicator at 9 o’clock, for the chronograph’s 30-minute counter and the leap-year display at 3 o’clock, and the analog date and the moon phase at 6 o’clock. The organized layout of the dial makes this differentiated information legible at a glance. Like the case, the dial is also accented with diamonds: a baguette diamond is set prominently at 12 o’clock, the keystone of a wreath of six round hour-marker diamonds in white-gold chatons.

This outstanding timepiece is worn on a shiny black alligator strap. Its platinum prong buckle is set with six baguette diamonds totaling about 0.3 carats.

The new Ref. 5971 chronograph with perpetual calendar is Patek Philippe’s only haute joaillerie watch in the Grand Complications category. It replaces the Ref. 5071 (column-wheel chronograph with 30-minute counter and seconds subdial).

Movement
		Caliber CH 27-70 Q Manually wound mechanical movement, chronograph with 30- minute counter, perpetual calendar, day and month in apertures, date and leap year by hands, moon phase, 24-hour indicator, seconds subdial
Diameter	:	30 mm
Height	:	7.20 mm
Number of parts	:	353
Number of jewels	:	24
Power reserve	:	Min. 50 hours, max. 60 hours
Balance	:	Gyromax
Frequency	:	18,000 semi-oscillations per hour (2.5 Hz)
Balance spring	:	Breguet
Functions	:	Two-position crown: - Pulled out: to set time - Pushed in: to wind watch
Functions	:	Two-button chronograph: - Start/stop at 2 o’clock - Reset at 4 o’clock
Displays	:	Hours, minutes, seconds at 9 o'clock 30-minute counter at 3 o’clock Date at 6 o'clock 24-hour indicator at 9 o’clock Leap year at 3 o’clock Apertures: - Day of week between 11 and 12 o’clock - Month between 12 and 1 o’clock - Moon phase at 6 o’clock
Corrector buttons	:	-Simultaneous day and date correction between 11 and 12 o’clock - Month correction between 12 and 1 o’clock - Moon-phase correction between 6 and 7 o’clock - Separate day correction at 10 o'clock Included: correction stylus in ebony and platinum with a small emerald cabochon
Hallmark	:	Geneva Seal
Features
Case	:	950 platinum, delivered with solid platinum and sapphire-crystal case backs, caseband diamond of about 0.02 ct. at 6 o’clock Water-resistant to 25 meters
Case dimensions	:	Diameter: 40 mm Thickness: 12.89 mm crystal to case back Overall thickness: 13.2 mm crystal to lugs Width between lugs: 21 mm
Dial	:	Black lacquer Baguette diamond index marker at 12 o’clock and 6 round diamonds set in 18K white-gold chatons Railway-track minute scale and tachometer Leaf-shaped hour and minute hands in 18K white gold White baton-style 30-minute-counter hand Rounded, leaf-shaped subsidiary seconds hand in 18K white gold Stamped leaf-shaped calendar hand in 18K white gold White counterbalanced seconds hand
Precious stones	:	Case set with 6 round diamonds totaling approx. 0.05 ct. and 1 baguette diamond of approx. 0.004 ct. Bezel set with 36 baguette diamonds totaling approx. 3.88 ct. Prong buckle set with 6 baguette diamonds totaling approx. 0.3 ct.
Strap	:	Hand-stitched alligator, shiny black. 16-mm prong buckle in platinum