Jaeger-LeCoultre Caliber 812 – Technical Overview from Document 1134_JLC

The Jaeger-LeCoultre Caliber 812 is a refined manual-winding mechanical movement from the mid-20th century, designed to deliver precise timekeeping within a compact and elegant form. Document 1134_JLC offers a detailed technical breakdown of this caliber, including specifications, component layout, and servicing instructions, making it an essential reference for watchmakers and collectors alike.

Technical Specifications

• Type: Manual-winding

• Functions: Hours, minutes, small seconds

• Jewels: 17

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

• Power Reserve: Approximately 40 hours

• Diameter: Approximately 23.3 mm

• Height: Approximately 3.9 mm

The movement’s size and slim profile make it suitable for refined dress watches emphasizing both performance and aesthetics.

Movement Architecture and Features

As detailed in document 1134_JLC, Caliber 812 features:

• Small seconds subdial positioned at 6 o’clock, driven by the fourth wheel and pinion

• Two-bridge construction ensuring durability and ease of maintenance

• Robust gear train and mainspring barrel optimized for smooth energy transmission

• Shock protection on the balance staff for impact resistance

• Manual winding and setting mechanisms designed for smooth operation and reliability

Servicing Notes

• Lubrication: Synthetic oils applied to key pivots and escapement jewels; light grease on barrel arbor and winding components

• Regulation: Aim for amplitude between 250° and 280° and beat error under 0.7 ms

• Small seconds mechanism: Check proper engagement and clearance of the fourth wheel pinion and seconds hand to prevent stuttering

• Keyless works: Regular inspection of the setting lever spring and sliding pinion to maintain smooth crown functionality

Applications

Caliber 812 was used primarily in:

• Jaeger-LeCoultre dress watches from the mid-20th century

• Models featuring classic small seconds displays with elegant dial designs

• Timepieces crafted in stainless steel or precious metals, generally sized between 33 and 35 mm

Conclusion

The Jaeger-LeCoultre Caliber 812, as outlined in document 1134_JLC, exemplifies traditional manual-winding movement craftsmanship with reliable performance and refined aesthetics. Its combination of compact size, precise engineering, and ease of servicing continues to make it a sought-after caliber among vintage watch collectors and professional horologists, reflecting Jaeger-LeCoultre’s dedication to mechanical excellence.