Jaeger-LeCoultre Caliber 849 – Technical Overview from Document 1151_JLC

The Jaeger-LeCoultre Caliber 849 is a manual-winding mechanical movement known for its ultra-thin design and simplicity, often used in elegant dress watches. Document 1151_JLC provides a detailed breakdown of this movement, including its specifications, structural components, and servicing instructions. The caliber is distinguished by its minimalistic approach, featuring only essential timekeeping functions without additional complications.

Technical Specifications

• Type: Manual-winding

• Functions: Hours and minutes (no seconds hand)

• Jewels: 17

• Frequency: 21,600 vibrations per hour (3 Hz)

• Power Reserve: Approximately 34–38 hours

• Diameter: Approximately 20.0 mm

• Height: Approximately 1.85 mm

The very slim profile and reduced diameter make Caliber 849 ideal for ladies’ watches and ultra-thin men’s dress watches requiring minimalist movements.

Movement Features

According to document 1151_JLC, Caliber 849 includes:

• Two-hand display focusing on hours and minutes, allowing for a minimalist dial design

• Extremely thin barrel and gear train optimized to reduce thickness without sacrificing durability

• Shock-protected balance with a simple, efficient escapement suitable for everyday accuracy

• Simplified motion works that prioritize low friction and ease of assembly

The movement’s layout emphasizes ease of servicing despite its miniature size.

Servicing Notes

• Lubrication: Critical to apply very fine oil at the escape wheel pivots, pallet stones, and balance staff. Barrel arbor and winding mechanism require light grease to reduce wear.

• Regulation: Achieve stable amplitude (~270°) and minimal beat error (<0>

• Assembly caution: Due to the thinness and small parts, delicate handling and precise alignment are essential to avoid damage.

• Winding system: Smooth manual winding action must be ensured, with no excessive play in the crown or stem.

Applications

Caliber 849 was used primarily in:

• Ultra-thin dress watches, including many ladies’ models

• Watches demanding a clean, minimalist dial without a seconds hand

• Timepieces with slim cases, often under 7 mm thick, emphasizing elegance and comfort

• Both Jaeger-LeCoultre and LeCoultre branded watches, especially for markets requiring smaller-sized watches

Conclusion

The Jaeger-LeCoultre Caliber 849, as detailed in document 1151_JLC, is a masterclass in mechanical miniaturization. Its two-hand simplicity, combined with an ultra-thin and compact construction, makes it a sought-after caliber for refined vintage wristwatches. The movement’s delicate yet robust design reflects Jaeger-LeCoultre’s dedication to producing elegant, precise, and serviceable timepieces even at the smallest scales.