Vintage Watch | Longines Ultra-Chron Automatic 7851

Longines Ultra-Chron Automatic 7851 – High-Beat Precision with Original Bracelet

Discover the precision of a true high-beat pioneer with this Vintage Longines Ultra-Chron Automatic, reference 7851. Powered by the legendary in-house Caliber 431 beating at 36,000 vibrations per hour, this late-1960s Swiss classic was marketed by Longines as “the world’s most accurate watch,” guaranteed to within one minute per month. Fully serviced and now running at an impressive +1 second per day, this example stands out as a rare, exceptionally well-preserved find.

A Landmark in High-Frequency Watchmaking

Introduced in 1967 to mark Longines’ centenary, the Ultra-Chron line placed the brand at the forefront of the high-beat race alongside Girard-Perregaux and Seiko. The Caliber 431 used a special molybdenum bisulphide dry lubricant to handle the increased friction of its 5 Hz rate, delivering smoother seconds and superior positional accuracy. Adjusted in multiple positions, it far exceeded typical chronometer standards of the era and remains one of the most significant mechanical movements of the late 1960s.

Timeless Cushion-Case Design

The stainless-steel case of the 7851 measures approximately 34–35 mm across, with a refined cushion profile that sits comfortably on the wrist. Clean lines, applied markers, and a silver dial free of any aging give the watch a crisp, elegant presence. The date window at 3 o’clock adds everyday practicality while the “Ultra-Chron” signature proudly announces its high-frequency heritage.

Exceptional Condition & Original Bracelet

This piece has been fully serviced and is keeping time at just +1 second per day — outstanding performance for a 36,000 bph vintage movement. The dial shows no aging whatsoever, and the overall condition is excellent to amazing. Completing the package is the original Longines bracelet with its original buckle, which lends a strong vintage retro vibe and enhances the watch’s authentic period character.

Why This Ultra-Chron Stands Out

High-beat Caliber 431 examples in this level of preservation, especially those still wearing their original bracelet, are increasingly scarce. This 7851 offers both the technical intrigue of one of Longines’ most important movements and the wearable elegance of a classic late-1960s dress watch. It is a compelling addition for collectors who value genuine Swiss innovation and outstanding mechanical performance.

Specifications

Maker: Longines

Model: Ultra-Chron Automatic 7851

Era: Late 1960s / circa 1967–1970

Case Diameter: 33*38mm 

Lug Width: 18 mm

Case Condition: Excellent to amazing vintage condition

Dial Condition: No aging, pristine

Movement: Fully serviced by our watchmaker in Japan. automatic Caliber 431, 36,000 bph, currently +1 s/day in amazing time keeping condition 

Bracelet: Original Longines bracelet with original buckle

This rare high-beat Longines is ready to wear and enjoy. Let us know if you would like to pair it with an additional strap for versatility.