Patek Philippe

In 1953, Patek Philippe unveiled their first automatic wristwatch, the legendary reference 2526. Powered by the esteemed caliber 12-600, it was renowned as one of the finest automatic movements ever created. Just a few years later in 1960, the reference 3428 was launched to replace the reference 2526. 

Despite substantial investments in developing cal. 12-600, Patek Philippe observed minor enhancements, after its customers utilized it in real-world conditions. These improvements, such as ball bearings for the automatic rotor, winding trigger reinforcements, different screw setting on the winding weight etc., were gradually integrated throughout the 1950s. Since these upgrades were minor, the caliber name never changed, at least not until Patek Philippe deemed to have achieved perfection.

In the late 1950s, the culmination of these enhancements resulted in the final iteration, cal. 27-460, prompting a renaming of the movement and the introduction of a new reference number: the present ref. 3428. Identical to ref. 2526 but featuring the new caliber, this model epitomizes what Patek Philippe deemed the optimal evolution of the best automatic movement of its time. Produced only until 1965, the reference 3428 also stands out for its rarity compared to its predecessor.