When we hear "early Patek Philippe Automatic" we immediately think of the original Cal. 12-600. Well, at least I do. But of course developments didn't stop with the first execution in 1953 and in 1960 (until the mid-1980s) the second and improved automatic Patek Philippe caliber was launched - the lesser talked about 27-460.

February 14, 2024

Evolution at Patek Philippe - The History of the Automatic Caliber 27-460  

    Marcus Siems @siemswatches
    Collector, Author, Data Analyst

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When we hear "early Patek Philippe Automatic" we immediately think of the original Cal. 12-600. Well, at least I do so. But of course developments didn't stop with the first execution in 1953^[1] and in 1960 (until the mid-1980s) the second and improved automatic Patek Philippe caliber was launched - the lesser talked about 27-460^[2-4].

 

The Heart - the Caliber 27-460(M - with date) beating inside a white golden ref. 3445. Photo from Goldammer Archives.

 

As the name suggests it's been a 27mm wide movement with 4.6mm height. Hence, the Caliber 27-460^[5]. In terms of technological evolution with respect to the Cal. 12-600 we're speaking here of upgrades to the Gyromax balance (thus dropping the swan-neck regulator), the Breguet hairspring, and the rotor ball bearings^[6].

Importantly, Patek Philippe further developed the movement into the base for many of their calendar watches of the time including the first automatic date watch on the reference 3445 (1961) and even automatic perpetual calendar timepieces with (ref. 3450) and without (ref. 3448) leap year indication.

 

Interestingly, the Caliber 27-460 served as base for a new branch from Patek Philippe: Automatic calendar watches. The ref. 3445 (depicted here) was indeed the very first automatic calendar watch from Patek, launched in 1961.Photo from Goldammer Archives.

 

Overall, we're speaking of 6,900 time-only movements (production 1960-67; movement No. 1,110,000-1,116,999^[4]), 13,100 with date (27-460M; 1961-86), 586 perpetual calendars with moon-phase (27-460Q; 1968-81), and 244 perpetual calendar pieces with leap year indication (27-460QB; 1981-85), a total of 20,830^[5].

 

Reference Guide

To keep things simple for now I will focus this guide on the time-only** pieces that have been in production predominantly during the 1960s. It is thought that originally the references 3425, 3440 and 3444 kicked things off with the new caliber in 1960 - all housed in 2-piece waterproof cases from different case makers.

 

Overview over Patek Philippe time-only references with the automatic Cal. 27-460. Photos Courtesy of Antiquorum, Christie's & Sotheby's.

 

Overall, we're speaking about (at least) 16 time-only references featuring the Cal. 27-460. Eight of these probably started production already in 1960. Some of these were upgraded versions of their respective Cal. 12-600 ancestors, some completely new designs. Here's the full list...

 

(This is where you might wanna flip your phone)

Ref. 3425

    Period: 1960-66
    Production: 31* (28* YG, 3* WG) 
    Movement: Perpetual (Cal. 27-460)
    Specifics: Wenger case (33.5mm)
    Source: AQ HK May 2020, Everywatch

 

Ref. 3428

    Period: 1960-65
    Production: 1000 
    Movement: Perpetual (Cal. 27-460)
    Specifics: 35.5mm, enamel, post-2526
    Source: Phillips Nov. 2019 HK

 

Ref. 3429

    Period: 1960-63
    Production: 1000
    Movement: Perpetual (Cal. 27-460)
    Specifics: Wenger Case (35mm), enamel
    Source: Christie's Geneva Nov. 2020

 

Ref. 3433

    Period: 1960-65
    Production: 500 (400 YG, 5* WG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Wenger Case (36mm), Stern dial, stepped bezel
    Source: Christie's NY July 2017

 

Ref. 3435

    Period: 1960-70
    Production: 500
    Movement: Perpetual (Cal. 27-460)
    Specifics: 34mm, post-2584
    Source: Phillips HK Nov. 2018

 

Ref. 3438

    Period: 1960-62
    Production: 5* (5* YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Gerlach Case, post-96 (31mm)
    Source: Phillips HK May 2019, Everywatch

 

Ref. 3439

    Period: 1960-66
    Production: 12* (12* YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Gerlach case (32mm), post-3403
    Source: Christie's NY July 2017, Everywatch

 

Ref. 3440

    Period: 1960-67
    Production: 50* (50* YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: 34.5mm, domed bezel
    Source: Sotheby's Geneva May 2021

 

Ref. 3444

    Period: 1960-63
    Production: 200 (200 YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Baumgartner case (35mm), special marker, enamel
    Source: Sotheby's NY June 2021

 

Ref. 3452

    Period: 1962-63
    Production: 2*
    Movement: Cottier Perpetual (Cal. 27-460)
    Specifics: Dual-Time, 39mm
    Source: AQ Geneva Apr. 1994, WatchProSite

 

Ref. 3454

    Period: 1961-63
    Production: 100-200
    Movement: Perpetual (Cal. 27-460)
    Specifics: Gerlach case (35mm), fluted bezel
    Source: Sotheby's NY June 2021

 

Ref. 3466

    Period: 1962-70
    Production: 1000 (1000 steel)
    Movement: Perpetual (Cal. 27-460)
    Specifics: 35mm, steel only, downturned lugs
    Source: Christie's HK July 2020

 

Ref. 3473

    Period: 1962-65
    Production: 100 
    Movement: Perpetual (Cal. 27-460)
    Specifics: 35mm, hand-reeded bezel
    Source: Sotheby's NY June 2021

 

Ref. 3485

    Period: 1963-70
    Production: 13* (9* YG, 4* WG) 
    Movement: Perpetual (Cal. 27-460)
    Specifics: square Ponti Genari (31mm)
    Source: Phillips Geneva Nov. 2019, Everywatch

 

Ref. 3525

    Period: 1965-75
    Production: 14* (9* YG, 5* WG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Croisier cushion case (32mm)
    Source: Collectability, Everywatch

 

Ref. 3542

    Period: 1966-69
    Production: 5* (5* YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: Gerlach case (36mm), stepped bezel, Roman Numerals
    Source: Everywatch

 

Ref. 3561

    Period: 1968-70
    Production: 150 (150 YG)
    Movement: Perpetual (Cal. 27-460)
    Specifics: 35mm, transparent case back
    Source: MLG Oct. 2020

 

This overview thus accounts for about 4,667 of the total production of 6,900 produced Cal. 27-460. So a little under 2,300 movements, or one third, stay unaccounted so far. Most of these unknowns will likely compose the references for which we can only assign known-to-market quantities (indicated by asterisk). However, it is possible that a small proportion of these movements may have never been cased.

 

Figure 1. Production quantities of time-only Patek Philippe Caliber 27-460 watches (1960-75). Asterisk displays the sum over all known-to-market examples without reported production numbers.

 

 

** We stretch the definition of time-only a bit as ref. 3452 is a Cottier modified dual-time wristwatch.

 

References

^[1] Patek Philippe Caliber 12-600 - A Movement for the Ages; Marcus Siems, Goldammer Vintage Watches, [Link]

^[2] Patek Philippe Armbanduhren: Kultobjekte und und Wertanlage. Wissen - Märkte - Preise; J. Michael Mehltretter, Heel, Königswinter (2011).

^[3] Patek Philippe, Geneve; Martin Huber & Alan Banbery, Ineichen, Zürich (1982).

^[4] Patek Philippe Automatik Kaliber 27-460; HonorisDE, r-l-x, [Link]

^[5] Patek Philippe & Cie; Antonios Vasiliadis, Faszination Uhrwerke, [Link]

^[6] La Grande Dame des Automatiques Suisse: The Patek Caliber 27-460; The Horologium, TimeZone, [Link]

 

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