Longines Caliber 19AS – A Historic Automatic Movement with Central Seconds

The Longines 19AS is a vintage automatic mechanical movement introduced in the early 1950s, marking one of Longines’ earliest ventures into automatic winding mechanisms with a central seconds hand. It belongs to the highly respected 19-series, a line that firmly established Longines as a leading innovator in Swiss watchmaking during the post-war mechanical boom.

The 19AS was used in both dress and tool watches, offering solid timekeeping, durable construction, and aesthetically balanced design. It reflects a time when Longines produced most components in-house and tailored their calibers to support both elegance and technical resilience.

Technical Specifications

Key Features

• Central Seconds Hand: Unlike earlier automatic calibers with sub-seconds, the 19AS was one of Longines' first to feature centrally mounted seconds, making it more readable and modern in appearance.

• Bidirectional Winding Rotor: The 19AS used an early form of automatic winding with a bump rotor (pendulum-style), which pivoted in both directions. Though less efficient than later full-rotor systems, it was mechanically robust and required minimal maintenance.

• Manual Wind Option: In addition to automatic winding, the movement could be wound manually via the crown—a useful feature for watches left stationary.

• Fine Regulation System: Featured a micrometric regulator on the balance cock, allowing skilled watchmakers to finely adjust rate precision.

Movement Construction

The 19AS was built with traditional Swiss quality in mind. Key construction details include:

• Monometallic balance wheel with Breguet overcoil hairspring for enhanced isochronism.

• Incabloc shock protection on the balance staff, a relatively modern inclusion for its time.

• Large bridges and clean layout make servicing straightforward.

• Jeweling at critical friction points such as escape wheel pivots and winding train.

The rotor system included a spring clutch mechanism to prevent overwinding and to decouple during manual winding—an early technical achievement for Longines.

Applications and Watches

The Longines 19AS appeared in many high-quality wristwatches during the 1950s and early 1960s, especially in the Conquest, Admiral, and early Flagship series. These watches typically featured:

• Case sizes around 35–36 mm

• Domed acrylic crystals

• Solid screw-back cases with water resistance

• Silvered, champagne, or black dials with applied indexes

These models remain highly collectible today for their mechanical heritage and enduring elegance.

Servicing and Collectibility

• The 19AS is serviceable with modern tools, though original Longines spare parts (like winding gears or the rotor bearing assembly) are becoming scarce.

• Watchmakers familiar with vintage Longines movements value the 19AS for its logical construction and stable performance.

• When restored properly, watches with this caliber can offer decades of continued operation.

Collectors seek out original, unpolished cases and signed dials, as well as models with engraved case backs or enamel-filled Longines emblems.

Conclusion

The Longines 19AS is a foundational movement in the brand’s history—an elegant yet technically solid automatic caliber that marked Longines' evolution into self-winding watchmaking. It combines vintage charm with engineering clarity, making it a treasured choice for collectors of mid-20th century Swiss timepieces. Whether powering a classic Conquest or an early Flagship, the 19AS stands as a testament to Longines’ mechanical heritage.